Yeah, I guessed they are 1 MB simms but from what I could dig up myself I wasn't quite sure. Don't know what's wrong though since the GVP controller doesn't accept them as such. It seems more likely that it's the controller that's broken somehow. The SCSI interface works just fine, the memory part not so much.
Oh well. Hope I can find some other simms to test with. Seems to be some on ebay so might give it a try with 2x4MB