Beseler Reflex Camera Back for 45M Enlarger

I just picked one of these up to make copy negatives of old family photos, however this one came without the graflok back.

I have one from a Crown Graphic that I can use for the project, but I'm not sure how it attaches. The thing came to me in pieces.

The holes on the back and housing don't align as it is. Does anybody know how the back attaches? It looks like I can fabricate something to fit between the housing and the back, but I'd like to know how it's designed to work.

Thanks,
Chris

Well, having little patience I decided to build the apparent missing part out of a sheet of 1/4" black polycarbonate. I bolted everything together and screwed my Graflok back on and took it for a test drive.

Since I'm using a shutterless enlarger lens for the taking lens, I shut off all the lights in the darkroom and plugged my illuminating spotlight into my electronic timer.

1/2s @ f/32 on FP4 came out about a stop shy of my target. I think it was because the lamp took so long to get up to full brightness. I assumed the dimming time would compensate.

I still came out with a perfectly printable negative of my late father taken in 1941.

Even more stuff!!!

Pandino, Beseler makes[made] a great set of clamp on copy stand lights just for the 45M and your back. They can be had on the bay also...