KK:I must be wrong about your plant being Adriatic jh,if you say is not as good.
If it does not taste as good then is not Identical to Adriatic Jh,it is only similar,in leaf shape.
What I can see different,is that Adriatic jh is solid inside and your fruits have a little hole in center.
Both discrepancies could be that your plant is young,or not as healthy as Adriatic jh.
The leaf positively is identical to Adriatic jh,so grow them side by side and decide if they are the same!.
Solving the Adriatic jh mistery?,No,I can't say,where it came from.
Possibly,Adriatic jh type cultivars are grown all over Europe,and every country has a different name for it.
This cultivar is too good to be grown in only one country.
On the tree I received as Vasilika Sika,from my source,there is not one fully grown entire leaf,only 5 lobes,and some time with thumbs.
Very rarely as an exception you can find a three lobes,but entire ,never.
Adriatic JH,has many entire leaves,and not because it is diseased but because that is how it is.
Here are pixes of fruits and leaf,of the tree I have as VS,taken today.
The plant is starting getting ripe the first fruit.
It is late but the climate here was very cool and rainy,plus the plant is 4 years old only,so I am sure it will ripe earlier in a Summer like 2010 Summer which we did not have past 3 years.
Most ,my trees included this one have leaf rust,another problem that was not present in the past,and fruits do not look their best,due to same problem.