If you're not worried about releasing the magic smoke, opening the can shouldn't be a problem. [}
] I don't want to take the tape off mine until it goes from natural causes.
Check inside and take some pics. If it's anything like the IIsi PSU there'll be a removable power board in there or a fuse you can pull to take the PSU out of circuit and retain function of switch and power connector. Just wire your wart up to the power circuit using stuff off the shelf from your local hardware store.
One alternative would be removing the switch for use on a new wiring harness. Remove the RFI shielding so you have access to the nice big SCSI connector opening. install one of the short, cute little power strip/surge protector inside and hook the whole thing up to a power module assembly built fro UL approved parts.
Upshot would be that you can snake short power cords for Mac and HDD thru the back and power the entire system up with your switch. Lots of possibilities for baseline case/chassis based hacks from the real deal or an
@PotatoFi printed replica versions for power distribution and assorted goodies besides the SCSI2SD.