I like Keitt mangos and enjoy the sweet-tart pineapple flavor they usually seem to have. My tree is too young to bear. Prior to this Year, I have only been able to buy them hard green at local fruit stands. When picked green, they ripen up nice and sweet-tart.
  This year, I found a homeowner nearby with a large tree that agreed to sell me a bunch every week or so until they are gone. Some of the fruit were half colored with yellow and a bit of brownish red towards the stem. These riper fruit were still hard but softened after a few days. I was totally surprised to get strong coconut flavors and the pineapple flavor was still there, but muted. It was like eating a huge Pickering. The flesh only developed the coconut flavor when picked almost tree ripe, and softened a few days on the counter. At that stage the flesh is 95% orange in color.
 A picked green Keitt is a good to very good mango, one that is close to tree ripe or has just dropped and given a few more days is an excellent mango. The earlier season fruit, even if ripened to mush, still had the strong pineapple flavor and no coconut overtones. I enjoy them at both ripening stages, but prefer the fruit harvested later.

I have been there about 10 times,most recently about a month ago. Their online catalog isn't always accurate. On several occasions, I have checked their online inventory before driving 35 minutes to them,and they have actually had items that were listed as not in stock online. I imagine it might be because they would have to severely prune some of those trees to fit them in a shipping box,or sometimes the trees seem recently grafted or re-potted and small for the container they are in.
  The average person might recoil in horror at receiving a mango tree pruned back to the main leader to fit it into a box. (Personally, I feel the more leaves on a shipped plant,the worse it fares.) If in doubt,call and ask them to physically check to see if they actually have an item. Overall I have had mostly positive experiences with them,the exception being that very few of their jackfruit trees were actually grafted.Only a handful of the 20 something trees they had that day had graft unions or scars. Of course the varieties I was looking for were definitely NOT grafted trees,so I passed. It might be that they sourced them elsewhere, I remember some posts about other nurseries selling jackfruit seedlings with the name of the parent tree. Overall a bit pricier than other nurseries in the area, but they do have stuff no one else carries. I don't think their notify me function works,The last time I was there they had something in stock that I had eventually found elsewhere. Never got an email saying it was in stock.

 I was looking through articles online about avocado breeding and came across a few facts that gave me hope. Some fruits,like apples,might need over 10000 to possibly 50000 seeds to be planted to get a superior new variety,and the vast majority would be barely edible.
   Avocados and mangoes would seem to give a decent chance to at least get edible fruit from a seedling. Hass was selected from one of 300 seedlings when I looked up the history of avocado breeding. In one trial, seedling progeny of Hass gave something like 14 out of 400 seedlings with promise,and one line of these gave almost 25 percent promising seedlings,according to a plant geneticist named B.O. Bergh.
 I guess planting out Hass seedlings even in Florida might have a chance,if you planted enough.  If you planted out several hundred,maybe one or two would survive the climate and thrive?
  Last year during avocado season I bought about 150 local South-West Florida avocados to eat, mostly from the Painters on Pine Island from about Aug. to Feb. I saved every seed,bagging the saved seeds once a week in moist peat moss in a warm place until they began to germinate. I randomly set them out in a bed near my house about 6 by 10 feet to see what happened. The bed is in a very wet spot that gets lots of run off from my roof. A lot of them sprouted and then died of root rot.I also watered a lot from my highly saline well that causes salt injury to most avocados and mangoes.Some had bad leaf tip burn and died. Others grew fine but had small leaves. I finally picked the one best seedling and carefully dug and transplanted it out. It has leaves up to 10 1/2 inches long and about 3 inches wide, much larger than any of the others. It looks like it will be a strong tree with excellent foliage,new growth is very red,it has 2 side branches already at less than 3 feet tall. It may never produce fruit better than any of its possible parents, but at worst I will top work it in a few years if the fruit disappoints. It was from a fairly small seeded variety with a pointed seed. I remember buying Day,Catalina,Loretta(Haven't heard anything else about it in Florida but it was very good fruit), Tonnage, Ettinger (also a very good fruit that I haven't heard any other reports about in Florida) , Lula, and several others last year, All were pretty good, but I think these were the only possible parents with pointed seeds if I remember correctly.I didn't pick the fruit so I don't know what the leaves on the possible parent trees looked like. It was fun experimenting and now with only a little effort and space, I have a promising one out of 150 seedling that hasn't fruited yet but gives me hope.... If everyone with a little space tried this with avocados and mangos, in a decade we would have mangos and avocados covering the whole year in SW Florida.

I had very similar damage to several species of fruit in the Southeastern US.  The specific pest causing the problem in my location in South Carolina was a stone fruit pest,a weevil called plum curculio. Is this pest in Europe , or from Europe originally, or maybe you have a similar species?  I grew plums and peaches as well, and the damage on your mangos looks a lot like what happens to peaches or plums.It also attacked apples. The insect would cut a small semi-circular slit in the fruit to lay an egg and once hatched the larva would burrow and cause some damage but was unable to complete its life cycle in the wrong fruit species. This would explain what you see when you cut a fruit open.If plum curculio attacks the wrong species,the larva can travel and damage about an inch into the fruit before it dies and then the fruit tries to heal over. It also would attack pears but they were less susceptible to damage than apples. Stone fruits were completely ruined,but apples were mostly usable for home use when affected areas were cut out but too damaged for sale. I suspect your problem is an insect pest attacking the wrong species of fruit in a similar manner. With any fruit, once the skin is damaged,secondary fungal infections can ruin the fruit. In my case, if I sprayed with the proper insecticide at the time the damage first appeared, scars healed over and fruit was fine. Imidan was the best and safest insecticide for Plum Curculio if that is what caused the damage. Various species of stinkbugs can damage many species of fruit by sucking on them,but the fruit is usually just deformed and still usable for home use if it doesn't rot from secondary fungus infections.

I emailed Dr. Campbell but no answer yet. I suspect it may well have been something he collected,but would he remember one tree out of hundreds of samples collected that got propagated,or would he even know about it at all?

Same problem here, it still won't work if I type it in as normal search words on firefox or google, BUT when I type tropicalfruitforum.com directly into the internet address window at the top of screen it works. I am still having trouble with finding old threads,keep getting the error when linking to them from search word results from a browser. There is a bug there.... Same results from several different computers.
 I don't stay signed in,I log on each time. I was unable to get on for over a week until I tried the trick above.

I wonder if the dwarfing effect on the tree is due to the fact that it is surrounded by pavement. I have seen that trick used to dwarf fruit trees before, it is essentially like keeping it in a pot.