New instant film back for Hasselblad 500, 501, 503 series cameras

[mshchem]

The darkslide had classic sharp edges, burr edge, I very briefly touched the edges up with the first sandpaper I grabbed, 150 grit, will find some 400 and go over it again this weekend. Really hoping this thing works for checking lighting etc. Also just to make pictures.

 

[neilt3]

I'm considering getting one to adapt to Bronica SQ-AI.
I've recently picked up a Polaroid back for the Bronica that I could possibly swap back plates with .

Does anyone here have both a Bronica SQ-AI and a Hasselblad 500 to compare backs with to see if shape and size are similar ?
Fixings would presumably be different, but that's why I picked up the Polaroid back to use .