Seanny, yes you're right, it does seem to affect the fruit shape and rind texture. I was very surprised to see how different the two trees fruits are growing.
Ckitto, thanks for posting your fruit photos. I will post the Cocktail green fruits on the Lane Late orange tree. I will need to find the photos I took a week ago. The Cocktail fruits on this navel orange tree have the same shape and smooth skin as yours. It looks like your fruits are in bunches, the Cocktail grapefruit trees seems to get a lot of fruits on the branches. I had to thin the fruits on this grafted tree since there were so many fruits on the tree, it was bending all the branches to the ground. I used 10 heavy duty metal stakes (6 ft) to try to support the branches with fruits. I ended up removing half the fruits from every branch.
On my original tree where I grafted this Cocktail grapefruit scion wood 30 yrs ago, the branches are huge. The rootstock/interstock variety was a grapefruit tree. I didn't care for the grapefruit, so I top worked the tree, so it was only the Cocktail grapefruit branches.
You may have seen this photo before of the fruits on this tree, but I will post these again. The branches had so many fruits (30 on one large branch) but it did not break lucky for me. In the last few years, I ended up graft 8 other varieties on this tee.
This one is my mother tree. The Cocktail fruit on this tree is always large, about 1-1/2 lbs each. The skin/rind is not smooth, more textured, easy to peel skin off the flesh. Fruit is super juicy, others I give the fruit say it tastes great. I don't think it is the best tasting, but it is juicy and tastes good. I like the Valentine flavor more than the Cocktail grapefruit (personal preference). Another interesting point about this Cocktail grapefruit grafts is that this tree has huge thorns on the water shoot type of growth every year. Some of the thorns as the new growth hardens are 2-3" long, these are the longest thorns of all my citrus varieties.
It will be interesting to see how the ripe Cocktail fruits are on the Lane Late orange tree.
The source of this Cocktail grapefruit grafts is from my mother tree with the 30 fruits photo. The grafted Cocktail branches on this tree is vigorous, outgrew the orange branches 2:1, and it has thorns that are 1-2" long. The Lane Late orange tree has been in ground for over 5 years, and it was only 4-5 ft tall. My grafted Cocktail branches grew over 8 ft tall in 2 years and the tree looks overgrown. Once the fruits are done, I will cut back all the Cocktail branches down to 7 ft and keep it that size.