Correct, Stu. I'd rebuild in a heartbeat......but this is an old Craftsman (Harris? Smith?) from the 70's. Can't find parts for it. I figure replacement is best at this point.
Jake, thanks for the offer, but I was able to finish the job. I'm ok, for now. It's not totally unusable, just has a leaking diaphragm and pressure builds on the low side with the torch valve closed. Once you get a flame, it adjusts with the regulator rather than the torch. Can get by with brazing.welding ok, but I'd hate to try cutting. Don't think it would work.