So one of my bathtub faucets keep spinning, and the other leaks, so I want to get them replaced. I think they are stirling valves but I can't seem to find anything that remotely looks like these valves in the stores. As long as the threading fits, can I use any kind of valve? Second question is that I think it has a seat but have no idea how to remove it. I bought a tapered seat wrench, seeing the 4 grooves but its too small and there isn't any room to fit it all the way through. Any help would be appreciated in getting these seats out and finding a replacement.