Polaroid 405 to Sinar F2 compatability, Fuji FP100c 3x4 film

In Today's post I am trying to solve a technical problems with using smaller less expensive instant Fuji film, FP100c instead of the FP100c45, with a Polaroid 405 holder on my Sinar F2. The F2 is a very well designed camera keeping with the Sinar tradition. But it is obvious this Polaroid film back was not intended for use with this particular camera. There is a tab on the end of the 405 film holder which prevents the assembly of film holder and Graphlock back from seating properly. This tab projects too far and prevents the assembly from seating. Hitting against the camera standard. The full size 4x5 PA-45 holder does not have such a tab and it slides in and mounts without a problem. The Fuji made PA-145 holder is a slightly different shape and I am hoping that it will mount without this same problem but they are pricey even on eBay so I would prefer to know before I by another possibly miss matched piece of gear. Does anyone out in Internet land know or use the Polaroid holder with a Sinar F2? If so how did you get it to fit?

For those coming to this blog and reading the post I will elaborate. Fuji is now the only maker of instant film for large format cameras. They make two sizes of film 4x5 and a smaller 3x4 size. They have announced that they are discontinuing the 4x5 film but regardless the smaller size is and has been for some time much less expensive in the US. When I learned large format photography we would regularly use instant film as an interim step to check focus, shot composition and exposure. In the old days many Polaroid test images would be taken prior to making the real shots.

Part of Polaroid holder which prevents it from seating.

Tab preventing Graphlock back from seating in Sinar F2 standard

In the current world we large format film photographers must cobble together parts and supplies to make a viable work flow. If I cannot take test shots the large format will be of considerably less practical use for photographing architecture and interiors on location as it really helps you know what the shot is looking like before you leave a location. Often a shot takes a long time to set up and you must put things back the way you found them. So test shots are a real advantage.  Since the 4x5 instant film is being discontinued it will likely not be an available resource for the much longer. For the time being Fuji is still making the smaller 3x4 size and it is relatively affordable. So it would be at least an alternative solution allowing the use of the smaller (almost the whole frame) size film. The photos show the 405 film holder not fitting into the Sinar F2. Possibly someone can help having either found that the Fuji made holder works or having modified the Polaroid holder to fit. Thanks!