Stan, I'm just reading the last bit of this thread now, and I think THE best example of a variety that is stable and shows a variety of fruit shapes on a single plant is Prue.
http://tatianastomatobase.com/wiki/P...b=General_Info
It's one of the few varieties that I can ID by aroma of cut slices, I think the taste is outstanding and would suggest it as a variety to grow, for everyone.
Please note all the different shapes and sizes that Tania mentions, many of which you can see in the pictures.
Carolyn