It's a good tip Lorn, to know to look if the dubious feature is on the surface or all the way through. That will help me because currently every little blemish gives me a virus scare!
I find both the feathering and stippling interesting. Jim, I have some Fellner seedlings here grown from exchange seed and one of them, though not really stippled, looked to me as though it could produce stippled seedlings:
