A Moen 1225B cartridge will work for that. It's a Moen valve
Can anyone identify this bathtub valve brand? The house was built on 1974 and I am guessing it is the original, but the cover has been replaced and I can't find a brand name anywhere.
Is that the only "standard" Moen valve in old homes? Not sure how prevalent they were. My house was 1978 and my valves look just like that (I know they are Moen because all the trim and sink faucets are the same and say Moen -- on the ones you can still read). I have one leaking a small drip and two others holding fine. Can't say if they're original, since we've only been here a few years. Sadly no local shutoffs, so I can't just pull it and take it to a plumbing supply house.
Sorry to jump on your thread, OP -- I was about to post your exact question.