There is an apple rootstock that can be grown from seed. It's called Antonovka. I have seed I bought and am having trouble getting to sprout.
Another possibility is to buy a rootstock and Stool
it to reproduce it.
Fedco sells Antonovka, but is out of it. Cummins Nursery still has rootstocks for sale on the web. Probably because their store was closed? But if they sell that one I can't find it.
Antonovka is a rootstock from Russia and will produce a near full size tree. Another apple that can be grown from seed and reproduce accurately is Fameuse. That one is not used as a rootstock, maybe because it's an edible apple.