Hi Satellitehead,
You will notice some variations in leaf shape on the same tree, but there is almost always a more dominant leaf shape. Leaf shapes are how I particularly distinguish the different varieties by first glance, I keep everything marked so not to confuse varieties, but even when all my trees are outside and not looking at the name, I can tell the difference by leaf shape, bark texture and color. Bark color and texture I have noticed also varies from different varieties at times, not always. What you will do is notice the leaf shapes when the tree is mature, at least a couple years old, they will be more (true to variety) and that is when you can make a good judgment as to the dominant leaf shape of a particular variety. Some of the varieties I have like the Negronne, Valle Negra, had a Ronde de bordeaux but it didn't make it, these trees look very similar leaf shaped, but if you do more observing, you will find the differences even between these trees. Natalina and from what I have seen Hardy Chicago are very similar shaped leaves also. I will compare them this year, also with my Mongibello which is just fresh from Sicily, which I believe in the original ancestor to HC. Once leaf shape in particular I am going to check out more closely is the Celeste.
When rooting they will look very similar on alot of varieties, but best to start judging by leave shapes when they are at least 2-3 years old. Yes, leaves on the lower main trunk will generally always be very misleading as they are never the right shape.
Ciao
Thanks for sharing