Hi All, I am currently restoring an 8x20 banquet camera. I have taken it apart (photographing each step of the way so I know how to put it back together!) and have stripped the finish from the wood. A friend of mine, an excellent woodworker is doing some minor repairs to certain areas. His work has been so good that I have asked him to actually replicate each piece of the camera in mahogany. I have another friend who is a metal smith. He has agreed to replicate the brass parts (I will purchase bellows and gears etc. on line). When all is said and done I will have sufficient parts/pieces to make two cameras, the refinished original as well as a brand new one. However the thought occured to me that I can simply scale the back of the replica camera up to 12x20 from 8x20. That way I would have a choice in formats. My question is this: How do I caluclate the amount of extra width I need on the back. The image size of the 8x20 is not exactly 8x20 (something like 7 5/8 x20) and the slot for the film holder obviously has its own measurements to accept an 8x20 holder. It seems to me that I really need an extra 4 inches of width, n'est-ce pas? Or is it a bit more complicated than that? Would anyone on the board be so kind as to measure their 12x20 back for me so I may make one like it for my camera? I would need all the appropriate measurements including inside and outside dimensions, film holder size etc. I can then compare them to the 8x20 back to see where I need to add the extra room. Thanks, Craig K.