This would be interesting on what you might have.
I wouldn't give up, light frost could do it, most likely a pollination issue.

I wouldn't give up on it. E. plums are very mysterious about fruit set and some years flowers don't lead to fruit. I think it would be unlikely you've bred the fruitfulness out of the variety from a self fertilized seed.

However, a second variety might help. Self fruitfulness of plums is less reliable than cross pollinization with a compatible variety.

Hi, I too have an Italian Plum, not a Stanley. This is the first year it has blossomed and I cannot find a picture on the internet of shuck-split Italian Plums. How long did it take your plums to get to 1mm in diameter. I can already tell, after petal drop that some of the stems are weaker and will fall off. I hope they all do not. I did read an article from a major university, stating that when European plum trees blossom for the first time, the chances of it dropping all fruit is very good. Sad but true. I feel your pain. Mrs. G

I have a Purple Gage that is ten years old and still no fruit. I did mis-prune it for several years, but the tree is very late to bear genetically.

Scott