Don't know when these ones snuck in.
The AM-1b is gone. In it's place at a cheaper price is the TC-1 turnout controller. By the looks of the name it'll just do turnouts and nothing more unlike the AM-1b. Edit: The feedback feature was removed in the transition from AM-1b to TC-1.
The AM-1S is gone. It's been replaced by the AM-2S. The only thing I saw different was the AM-2S had a more powerful amplifier for sound.
https://ringengineering.com/TC-1.htmhttps://ringengineering.com/AM-2S.htm- Tim