I'm having a problem with getting instant film backs to fit under the ground glass on my old-school Calumet camera. I had a Polaroid 545 that worked fine but unfortunately, the film isn't available anymore. The camera isn't professional grade but it works (silver metal color with fixed bellows). I'm hoping there is some instant film solution to use with it.

I finally broke down and bought a PA-45. Unfortunately, the back doesn't fit under the ground glass. I'm wondering if anyone else out there might be able to help me determine if there is a back that would fit. This is what I have determined:

Polaroid 545 back thickness: ~1.5cm (fit, but film discontinued)
Fuji PA-45 back thickness: ~2.75cm (too thick)
Polaroid 550 back thickness: ?
Fuji PA-145 back thickness: ?

My camera has about a 2cm max allowance under the ground glass.

If anyone has a 550 or 145 back and can tell me the thickness, I'd appreciate it. Or, if anyone knows an option for replacing the metal tension element holding the ground glass, I'd be interested in knowing about it.

Thanks....