So far as I can see by looking at the photo of the open back shown (link in post #4) the felt bar (or whatever material it is) shown on the F7 is a light barrier to prevent any stray light from the lens from fogging the exposed film on the take-up spool.
That is what I figured. Is that foam pad, the only foam pad in the camera? If so I will have to buy some foam and figure out what type of glue to use on it.
Warning!! Handling a Hasselblad can be harmful to your financial well being!
Nothing beats a great piece of glass!
I leave the digital work for the urologists and proctologists.