Finally decided to take another crack at this thing. It's been 5 months since I opened it up but I wasn't able to find any manufacturer name or other markings without taking the board out. However, the board would not slide out since the add on card was too tall and the surface mount components were hitting the chassis. Had to bend the side of the metal out and pop the board out from the bottom.
Check out the board, a few cool things going on here:
It appears to have 2 separate upgrades. First is the 2 Meg "Fat Mac" upgrade from Perspect Systems Inc. out of Venice, CA:
Not too much out there about this company, but did find this ad in MicroTimes from 1986:
https://archive.org/details/microtimesvolume00bamp_14/page/n21
The case also has a cooling fan added to the rear vents with power tapped from the analog board. Not sure if this is separate or part of the Fat Mac upgrade.
Also found this reddit thread for someone else who apparently found one of these.
https://imgur.com/a/bemqL
Second is this SCSI board from Julian Systems Inc.
This is my main focus at this point. I unplugged the SCSI cable but didn't remember or document which way the cable was installed. It has a red stripe on one side for pin 1 I'm guessing, but this SCSI board isn't keyed and I'm not sure how it goes back on. I suppose I should look at the SCSI pinout, find a ground or something and follow a trace on the board. Have to do some more research but not plugging it back in until I'm sure its right.
@unity Yup, you were right, the battery area was shaved for the cable to go through. But I reinstalled it, the cable got pinched a little. Bummer. It doesn't look bad but a simple continuity test should confirm it's ok.
Another shot of the board showing overlap between the ram board and SCSI. While I was attempting to remove the board from the chassis, the ram board actually pressed down on the SCSI board and it unseated it from the rom socket below just enough where the Mac wouldn't boot, just showed checkerboard on the screen. Re seated it and everything was ok but there was a moment when I got really disappointed, thought I killed it!
Here is the 2048K as she sits now. Still got a lot of work to do, none of the drives eject, gotta figure out the SCSI cable, its a bit dirty and there are some cool peripherals that came with it that I can't wait to try out. But I think that will be a separate thread.
Just thought I would update this thread since I wasn't able to find much online about this setup.
And thanks to
@Dog Cow for the work on his 512k site, lot of good info that helped me through this process.
https://macgui.com/news/article.php?t=470
https://macgui.com/news/article.php?t=471