Nice pics!!
So now I get it. There's a cable sticking out of the back (probably through the security slot) that connects the hard drive to the SCSI port.
I bought a Plus ED, which I'm sure you're familiar with, mactjaap, since it's from the Nederlands ;D . I plan on adding an internal SCSI drive to it.
It doesn't work right now, but I'll fix this guy sooner or later. Need to order some caps now.
Could you please take a picture of where the molex connector wires originate from on the analog board? I think I have a pretty good idea of where to get +12 and +5, but since I'm not an EE at all, I don't want to risk hurting my Mac too much