I’m new here and new to the Curta world. I’m actually looking to buy a Curta as a gift for a young engineer. I’ve started my research here, on other websites and on eBay. I would like to find a working (excellent condition) collector piece and I believe I have narrowed down what I’m looking for. I think I’m in the market for a series 2 early black metal version as I prefer the metal version but think the series 2 would be appreciated. Is there a scale of value- for instance (condition being the same) the most valuable would be X (maybe prototype), then Y (first of the series 1), then
Z (possibly metal series 2), followed by later series 1 and finally series 2 later?

Also, other than eBay, where would one look for these from a reputable seller?

Thank you.

Just for clarification: All Curtas are made of metal. The later gray Curta II are just painted gray as opposed to the black ones, which are anodised.

There is a difference in the canisters, though. The later ones (on pictures you can recognise them by their protruding thread) are indeed made of plasic. But if you are looking for an early black Type II that shouldn't bother you - the plastic canister came long after the color switch to gray took place.

That said, early black type II in good condition are rare, and so they are sold at a premium. But you probably found that out by now.