A branding question, more "retro" than vintage
 

We got a Simplicity 9150 model in the shop today, mostly metal body with what is probably plastic innards, as much as could be gotten away with. It's "new" enough to have a 1-step button hole stitch but not new, by any standards. 13 stitches, no 'puter, not even self-threading. So the question is, who makes (made) Simplicity machines in the 80's-ish. i.e. what big corporate parent actually produced these guys before they were badged off label? Any ideas? Is there any way to see the corporate family tree for these types of things? TIA!

I have a Simplicity 9420, and most of the parts are interchangeable between some Brother and Baby Lock machines, though I don't really know if Brother was the manufacturer responsible for the machines, but that would be my guess.

When my DH was in Korea in the 80s he mentioned knowing someone who said Singer and Brother were manufactured side by side in the same facility at that time. And I had also heard that Simplicity was similar to both.

All of this is at least third or fourth hand info so I can't actually verify it.

I do know from personal experience that feet and attachments are interchangeable on all three.