If the tree was grafted and your new growth is from below the graft the one thing you can be sure is that it won't be a Victoria (wouldnt need to graft to same root stock) so you may be in for a surprise. I've a feeling they sometimes graft onto damson rootstocks.

There are some other self-fertile plums if you are looking to replace, but do check with a reputable supplier about a suitable rootstock as plums can get quite big, and the choice of stock determines how big it gets.

Best of luck, I can almost taste the results.