Today I bought a fairly expensive Derogy Petzval on ebay. It went higher than I thought it would. SO, I need to sell a few other pre-Civil War Petzvals that I'm not using, so my wife won't holler. At least, not as much. I don't really need cash RIGHT NOW, and can wait some months to sell. I generally try to buy camera gear in late January or February as prices are at a low ebb. However, that's with "regular" stuff, not the vintage/historic stuff. Is there a "best month" to sell this kind of stuff? I have three Petzvals including a 6 inch Derogy, 4 inch Grubb, and 165mm Voigtlander (serial dates to 1865.) I've been shooting them on a 4x5 Chamonix.

Second question is about flanges. The Derogy has its original flange, but the Grubb and Voigtlander don't have one. Would I be better off getting flanges from SK Grimes, or is not having one a major negative?

Kent in SD