Whitechapel MG-1 workstation questions

There's a trick if the machine won't power up at all... The power switch on the MG1 is software-controlled (!), and it runs off 5 AA NiCd cells on the power distribution board (these also keep the RTC running). They're charged when the machine is running, but of course if you leave it powered-down for too long, they go flat, and you can't turn it on agaain. The way round this is to connect a 9V battery (a PP3 or similar) to 2 of the pins of one of the connectors on the power distribution board (I can get the exact details). The machine will then power up, and you leave it running until the NiCds are charged

A few initial questions after a couple of these beasties turned up at the museum: Does anyone have OS install media for these? We've got the manuals, but no floppies and I'm not sure what state the hard drives are in yet. Don't suppose anybody has schematics / service information? Predictably, the batteries inside the machines are toast and have taken half the circuitry with them (grr!). I'll clean everything up and then bypass the tracks which have been damaged / eaten away. Presumably there's a trick to starting these things after battery failure by feeding power straight to the internal relay - any ideas what voltage it needs though? And once running will I still need to keep the relay energised or will the PSU circuitry take over (even in the absence of batteries - I'm just going to remove the damn things completely)? I've got one hard drive to spin up and become ready after dumping half a can of WD40 onto the bottom spindle bearing - it wouldn't even turn before that. Now it just sounds like a sick cat. :-/ Hopefully it'll last long enough to get any useful data off it though. I notice what seems to be a SCSI connector on the system board - can I pull out the ST506 disks and just run a more modern (and hence reliable) SCSI disk from here? Or is the SCSI connector (if that's what it even is!) just designed to support a tape drive, and the machine always expects the boot drive to be an ST506 disk? cheers Jules