Marsh Creek Farmstead: New to Grafting

New to Grafting

Ive never grafted anything before and with my new found love of plant propagation I'm become very interested in all methods of plant propagation.  I've purchased a grafting pruners, self sealing tape and pruning sealer. The grafting pruners I purchased can be found in my amazon store.
My first graft was on a plum tree that has been in growing for 30 years and I have never been a big fan of the fruit. It always produced a fruit that was pretty small and on the bitter side. The scion wood came from an interesting source...a crabapple tree that started producing a delicious plum this year. 
I think the root stock of the crabapple must have been plum of some sort.
I hope these grafts take and I can put some new life into this old tree.