Chips are the same numbers as the other unit, but earlier date codes.
This is problematic, as I've noticed that the tmc0351 and 2 from a MTA1179 board and the tmc0351 and 2 from a 1980 board do not have the same contents, but do have the same part numbers. Same with the TMC0271 from the MTA1179 (which has the module 'bug') and the one from the 1980 board (which doesn't). (maybe at some future date we can try to dump them? I think it may be possible to do using probes on the 4 data lines and otherwise through the edge connector itself)
I frankensteined a working S&S from the two that I got, using the PCB with the older chips. It definitely has the "no module bug". I pulled all the chips from the other PCB. I was hoping they'd have some further ID numbers on the bottom, but they do not. A couple of them do have different die revisions than the other chips- the "newer" ones are TMC0271NL NBS 7910, TMC0351NL NBU 7906, TMC0352NL DAU 7901, TMC0281NL D 7906. The "older" ones are TMC0271NL DBS 7832, TMC0351NL DBU 7832, TMC0352NL DAU 7832, TMC0281NL D 7832.
I'll dump the ROMs, then decap the 4 chips from the broken board.