Quick update over here:
I still haven't gone into the display bezel, I'm just throwing a little salt over my shoulder and opening it real gingerly.
But I *did* build a new battery pack. I didn't have a lot of time, so I remixed a case on Thingiverse to just make a big empty box, then I used QuikSteel to place some electrodes, and wired up an off-the-shelf 6v NiMH AA pack. It's not the best battery life, but the construction was extremely cheap and easy. I will take some photos and share later, but here's my WIP emptied out case on thingiverse
https://www.thingiverse.com/thing:6114478/files
I also replaced the venerable IBM 120MB drive, which still booted and went to sleep and everything, with a new ZuluSCSI RP2040 mobile version. It's *mostly* working great, but I'm having trouble with it failing after it goes to sleep. I did also add a small variation that I threw on my Mac Classic one too: a piezo speaker on the external LED port! This adds a satisfying click to let you know the drive is doing something. I don't know which piezo I used, just one from the junk bin. OK thanks, more later.