Sadly, from the search I did, it would appear that
if anyone knows the part numbers for the SSM1, they aren't sharing. Probably because it was superceded by the SSMII and therefore nothing for it is available anymore even if you
did have the part numbers.
That said, I still don't think it's in the software. I don't think there's some special "1992 Interpretation Protocol" written in the SVX cartridge. I think it's all down to the actual connection hardware.
Which means I have to take back what I was saying earlier, sorta... maybe it
is the cable... or yeah it probably is...