I am betting it is Celeste just looking at the leaf pattern. If i am right, Celeste is good tasting. I believe what you have out there is in bush form tree with multiple branching. It sounds like the only thing you will invest in is TIME and LABOR. But since the tree is dormant, and mature..you may see fruits this year. No worries on rooting. It's already established. If your into grafting, you have plenty of stock. Spring is coming and then summer, if it bears that much, I would sell it to locals, "U pick" your own fruit on Craigslist- lol
Congrats Tony.
Jennifer