Call Jim Tucker. Don't email. Call.

http://www.heatercontrolvalve.com/

Ask him if he can rebuild yours. Some he says can't be rebuilt, but he does seem to have an inventory of originals for those, if you ask. He's not a good salesman - you have to pump him for information.

I bought a valve from him 6 years ago and was very pleased.

If you don't see two dolphins, you need a vacation.