No, the rear alternator is doing just fine. The "Standby/Run" switch worked as advertised. The front alternator fell apart (literally) during approach to destination. I had not paid the alternator switch any real attention until then. I have now had my attention refocused.
During pre-flight run up I have a set of toggles and meters that measure either battery or alternator levels of charge/discharge, as long as the needles said charging and the load was equal, I was a happy guy. We didn't get into the mechanics of the actual alternator switches until it came time to shut stuff down.
At my maintenance base (KRBD) there are 4 vintage 1974/6 337s. I looked at each of those and my set up is very different from them. The other 337 are all either P337 or T337s with 38 amp or more alternators.
Jerry