Have a look at this completly mixed up Curta with faked serial:

http://www.ebay.de/itm/Curta-Herzstark-Rechenmaschine-Typ-1-/131418251655?pt=Antike_Bürotechnik&hash=item1e99236187

Regards

Sebastian

Ha, you and Vincent caught the same one, on different eBay, good eye

Well, calling it a scam might be a bit strong. The three weak points in a Curta ar ethe crank, which breaks, the clearing ring, which also breaks, and for the early ones, the reversing lever, which is surprisingly fragile. If the reversing lever breaks, it necessitates exchanging the cover for the setting levers as well, because the slit in the original one was not deep enough. So this may well indeed be Curta N° 6123 - but with a number of sensible repairs or updates in the 60's or 70's - later revering lever, crank, and perhaps clearing ring, because it would surprise me if that would have remained intact if the crank broke.

Cris