Adapter ... mmyeah ... something like that
This thread and the project linked from it will give you some idea of what's involved. Granted, it's going the other way, but the complexity would IMHO be of a proximate order of magnitude.
Luckily, you're now three clicks away from a supplier of monitors that might be usable as is.
Which at first glance are all identical to the Mac itself.
Except wait WTF??
/edit/ I'm going to assume for the moment that the output is greyscale, and it is just necessary to have all pins connected.
Your mission should you choose to accept it is to post some better photos, scans preferably, of both sides of that device. See the Nubus Mafia pages at Applefritter.com for examples. Also, a trace of which pins on the connectors go to which points on the PCB would be handy.