The only real issue with this machine (as far as I know) is the NVRAM battery is toast.
This is a slightly bigger issue than it sounds like, as the battery is permanently encased in a big polymer blob on top of a chip.
There are a few ways to deal with this, one of which is to just carve away the top until you expose the battery contacts, and add a CR2032 holder somewhere.
So ... time to fire up the Dremel.
Found some terminals! A quick test with the multimeter found a miniscule amount of charge coming off the old battery. I'm not going to try excavating the whole thing today, just want to get the thing booted.
Well, it still boots, now to try rewriting the NVRAM contents, and see if it sticks.
NVRAM is surviving power off! Now to actually work on booting something.
Hmm, for some reason NetBSD won't boot from the CF card as easily as Debian does, so I'm just going to install Debian to check the hardware all works and set up a netboot environment later and skip the whole issue.
So when I got the NetBSD installer to boot, it black-screened on me - I suspect it was switching to serial console, not that it was broken. Rather than scavenge around and figure out a serial console, I tried #OpenBSD - and it worked perfectly.
I have a lot of cleaning up to do now, but it boots properly and now I can start installing things.
Bonus - an old USB PCI card I used to use in my Blue & White G3 Mac works great, and I can just use a USB stick to copy stuff now!
Turned out #Solaris 9 was a right pain. The installer actually crashed at certain points and I really didn't want to keep fighting with it.
While wondering if it was just a dodgy drive causing me grief, I pulled out the old CD-ROM and replaced it with an IDE DVD drive I had on the shelf - and ended up slapping a 120GB hard disk in it as well.
Consider this a friendly, local pub. Make yourself at home, bring your friends, have a good time! Meet new people, have a laugh, enjoy the ambience, and the Oxford commas.