Yesterday I made 20 small grafts onto the tree from my Dad's 2 apple trees. Unknown variety, he thought one might be a Delicious. Unfortunately, they had a day-long trip at room temp to get here, so may not be viable. The cambium layer was green and soft, so still worth a try. I may also have made a mistake, tying the graft together with dental floss, which I learned from a rose-grafting video. They are covered with teflon plumbing tape. We'll see.
Here is the result of my first attempt at grafting, 2 Springs ago. A a complete novice, I just cut the scion and base tree stems to match, tied them together with electrical tape, and that's it. This was the only attempt at the time. It grew that summer, and last summer. Looks like there might be a flower bud at the tip. I don't know the scion variety. The main tree is Liberty on M27 ultradwarfing rootstock.
Here is one result from last Spring, grafting from neighbor tree prunings for scions, onto Golden Delicious on M27. This scion grew like crazy, adding branches and about 16 inches of growth. One branch might have a flower bud.
Here is the other definite 'take' from the neighbor tree onto the Golden Delicious. Again, it grew well. The tip was frozen, so I pruned it back a little. It won't bloom this Spring but should grow as well as any other branch. This may be a tip-bearing, rather than spur-bearing, variety, so I don't want to get carried away with too many grafts.