Toronto. From time to time Skinner in Boston and Marlborough MA send me an email about up and coming auctions. Saturday (November 1, 2014) there is an auction covering Clocks, Watches, and Scientific Instruments. Included in this listing are cameras and lenses which are grouped with Scientific Instruments. There are a few Leica/Leitz items that seem a bit the worse for wear and priced accordingly.
In any case, have look at Skinner’s lovely online catalogues.