Scrappers love snipping off cables for that $.05 of copper. And to be honest people and companies tend to keep expansion boxes but lose the cables that are needed to use them. Those 5161 were probably not made in any major quantity.
Except that the 5161 isn't any different from an XT chassis, except that it doesn't have a speaker and is outfitted with a backplane. But who knows how many were produced; several of mine (including some fair to rough condition cases) that I want to sell came from IBM's Lexington, KY facility (more than likely what became Lexmark), with inventory stickers going up to 1990!
thinking of revisiting this system and trying to cram in even more cards - are there any 3-slot 8-bit ISA risers that were/are commercially produced with the slots on the right hand side? or should I just spin up another PCB?
Love this. Had a similar idea once to cram in both MDA and CGA cards to one slot. Got me thinking, could you just use ribbon cable and some IDC card edge connections? I guess length is going to be an issue, but IBM basically did it with their PS/2 model 55 "ESDI" HDD's. Just wonder how many cards you could ram into a 5150?