I do need to take pictures of the boards, but I need to find a good setup that doesn't underexpose or leave visible glare on them.
But - I'm rapidly running out of steam on this project... A sudden loss of confidence in my ability to draw a good schematic (there are two boards that are impossible to rearrange and unify without going to max sheet size). Finding all but two of the boards I sought has mostly satisfied my curiosity (of the two that remain, one is a potted assembly and the other is unobtainium - all I have for the latter is a picture). There were a few forum threads I made elsewhere seeking some information, and nobody has been interested enough to provide useful input.
And this after running into a similar brick wall on my other project on another system from that same era. Discouraged? Looks like I am.