Several of those holes were not made at the factory. God, that poor bass.
The good news is, you're part of the way there -- my first Alembic, also a Spoiler, was done over and later resurrected so I'm confident you can do it.
Those pickups look OK, and what's left of the electronics looks like an Activator system made for a Fender P. Since that's a one-pickup bass, it won't do. The control attached to the larger circuit board is a Q control, which is something like a wah pedal...there's an FAQ on the site somewhere you should read.
You can get the bass back in playing shape by ordering a Spoiler electronics harness, which is volume and tone controls and a pickup selector plus a switch to turn the Q control on and off, or you can do what I did which is luck into a used Activator setup and hope for the best. Be advised that didn't really work, though.
I like the idea of fabricating a koa cover for the boogered electronics...if you cut it thin enough it should do OK since the bass has a flat top, and it won't be the strangest mod I've ever seen done to an Alembic. Best of luck to you.
