I feel that there is an old lens in my future, perhaps one of the many brass Petzals offered in the for sale forum. I have searched the internet extensively and have found a lot of bits and pieces of information on these lenses; however, I have not seen anything that looks like a primer on the care and feeding of these old gems. I get the impression that all these lenses follow no standards as far as dimensions; that you have to be a machinist to mount them and for a shutter you generally use a hat. I know this is not entirely true, but I am bringing to wonder if perhaps they are only usable by the truly geeky inclined. I have an Arca Swiss 4x5 with 110mm lens boards and was wondering where to get information about getting some of these lenses to work with such a setup.