It's difficult to tell from this pic, but the cuts may be there for the rear base but I don’t see the base unless the mount was a good bit forward than typical. I agree that $2250 to $2500 USD are typical prices realized for Blitz combos. Lately I haven’t seen any for less that $2k and anything near $2k USD seems to move. There are only about ½ of a handful of German examples that would realize $25k USD from this period and a couple examples would be the Drilling taken from the Sauer Villa and Mr. Jone’s latest acquisition:
http://www.bobjonesguns.com/details.asp?id=C4514S . Franz Kettner(from 1840 to the 1960s there was a Sr. & a Jr. followed by a Eduard Franz Kettner) was a name used for a couple generations and Ed did have a gewehrfabrik in Köln a. Rh.(on Rhine River) und Suhl i.(in) Th.(Thuringia) as per his circulars, but actually he was a firearms merchant and outfitter. Franz Sr. did work for Franz Otto Julius Kettner in the 1880s, but left for greener pastures. From the one pic it looks to be a Blitz action with a Hornbugel(horn triggerbow). It resembles a Heym Model 137 or E. Schmidt & Habermann Model 580(Model 581 was an A&D). Does it have a cartridge trap in the butt? I also assume it has a single crossbolt lock-up? Additional pics would be of assistance especially on the underside of the tubes. Is it chambered for the 6.5X58R Sauer(S&S)?
Kind Regards,
Raimey
rse