He has the later style valve for 73. I just happen to have this valve from a 74 sitting in my tool box.
I just pulled it apart, just for you.
Can't get a good picture with flash at this time.
There's alot in there and I'm sure yours is messed up inside from soaking and not taking it apart.
This one was stuck and I still don't have the spool out of the inside. I can slide it back and forth with a peice of welding wire, so it's not stuck. There is a bunch of debris in the springs. With this one I would use brake fliud to clean it out, KEEP MINERAL SPIRITS away!!
I think I would reuse this one since the valve slides back and forth inside. I'm not sure how to get it out yet to really make sure it is funioning properly and clean. I'm gonna let soak for while and I'll report back.
On your car your going to have to remove the whole thing from the car to disasemmble or replace it.