Thank you for the warm welcome! I hail from Pennsylvania.
I think I'm going to take David's advice and leave the top alone, its only swayed by 1/8" or so, with a few nicks here and there, probably not enough to warrant serious repair? I'm mostly into woodworking, though I'd like to get into blacksmithing too. I've been using this anvil to straighten old handsaws. I know you're not supposed to hammer cold metal on the anvil, but the work tends to be pretty light, the saw blades are thin and straighten out with light hammering. I'll post a closeup pic of the top tonight.
Frank, when you say early British, do you mean mid-19th century?