Clayton - It would be wonderful if you could post your pages to Wikipedia, or somewhere. I don't know if pages found by web archive are good forever and ever, but I doubt it. I've heard there is a way to save entire web pages onto my computer, but don't know how to do it. I'm not shooting Cirkuts at all right now, mainly due to lack of time during periods of nice weather. Not many years until retirement, and taking a Cirkut out on a warm summer day is something I dream about.

Roberto - Regarding the focusing difference between your focusing back and Cirkut Attachment, I wonder if the camera body (or at least the focusing back) aren't original to the Cirkut Attachment? I have a 5X7 Kodak Pony Premo #9 that can be used with modern sheet film holders, but the ground glass needs to be installed backward (frosted side to the rear of the camera) in order to get accurate focus. I've never understood why, but I suspect it has something to due with the transition from glass plates to sheet film. There was a time when camera makers didn't all use the same standard depth-to-film for their film holders.

I believe gear pitch is a term indicating somewhat the number of gear teeth per length of measure. It may refer to number of teeth per inch of measurement around the circumference of the gear, but I'm not sure of that. I think the more formal name for pitch is something like pitch diameter or pitch circle and there is a formula that defines it. Somewhere online should be the precise definitions and formulas relating to gears. Another gear term is "pressure angle", relating to the profile of the individual tooth. As I recall, the pressure angle used for Cirkuts isn't as commonly used as it once was. Some people think you can go to a gear manufacturer's catalog and buy Cirkut gears, but getting the correct pitch, pressure angle, and number of teeth you want in a brass gear is very difficult. You are very fortunate to have obtained a Cirkut which includes gears for so many focal lengths of lenses.

Len