Very good info on this thread! Mark described it perfectly!This is my favorite hi-hat stand of all time. You can pick up a replacement wingnut for that clutch with nylon insert inside the thread. The thread size is fine thread 3/8" (3/8" x 24). You should be able to pick one up at a hardware store; look for "Nylon Insert Wingnuts".V
I didn't realize we were talking about the bottom nut. Yes, as V mentioned, it is a wingnut with nylon insert.
As to the spur-lok piece, I've never had to remove one, but I would think that the rod that holds it in place is just a friction fit and can be driven out with the proper size pin punch. And, yes, I'd keep the current foot board, rather than replace it with one that isn't as cosmetically nice!
-Mark