I was able to fix most of the bad keys on the good keyboard. Swapped a few springs out and one metal piece and the keys were back to normal. There's still one key that's giving me issues ("w") and I intend on desoldering the switch and replacing with a good one.
I also gave each side of the keyboard a very detailed clean with, compressed air, q-tips, and alcohol.
To protect the ribbon cable that connects each side from damage, I filed off a few plastic tabs. These were pressing down on the cable.
I've attached a photo of the switches for future reference.
So System 7.0.1 + tuneup was fine. Installed the Daystar cdev and it was fine. Upped to 7.5.3 and initial boot after install was perfectly fine. Copied afterDark files from my external SCSI and I got a bomb on reboot— error 10 / bus error. Tried to disable extensions on reboot and still got the bus error bomb. I'm wondering if I've got similar problems described here:
No screen artefacting thankfully. At work now, but later today I'll probably pull the ethernet card first and work my way back. Ethernet is pretty low on my ultimate 68k mac list, so it won't bother me if it has to go.
I also have that new GGLabs ROM and I wonder if installing that would solve anything going on here. But then that's got me wondering: does the installer hack described by Gamba (waybackmachine link) and BMOW described need to be applied to the GGLabs ROM if I install it? Or would this addition just be complicating matters?