Har I'm SURE 100% that it's grafted.
I still remember when my wife bought it it was still very visible the cleft graft at about 1ft from the soil. Actually until now you can still see a slight difference in bark grain between the lower lower seedling and the upper scion.
The trunk diameter is about 15cm (6in) and tree looks healthy.
I'll take some pictures next days.
I'm at just a few meter above seal level actualle see is just 600m far from me.
By the way, the little tree was bought together with another one "sibling" wich was planted in a different area (another island).
The tree flowered and fruited for the first time a few months ago.
I hope mine can manage to flower here, i don't want to keep a tree just for shadow!