Great, thanks for the responses. I will open up the SE tomorrow and attempt the transplant. I expected that I'd need the SCSI cable from the Classic II, so I've held onto that and I also have the metal mounting bracket (very heavy!) from the Classic II if that'll by any chance fit in the SE. I will try very hard not to be lazy this time; when putting things in PC towers sometimes I just electrically tape new things new HDs in based on gravity and general time constraints.

The logic board is in pretty poor condition. Anyone can have it for free if they want to pay the shipping - the amount of corrosion is very serious. However, it was able to have power pass through enough so that Simasi mac came on the screen, very stably. I feel like this means something.