Hello, Tinker:
I am only 25% "Herr" (German grandma)
Yes, I know the double rifle I have. I really like the Kersten lock of the Franz Sodia doubles and I searched some time before finding it...

I got the rifle cheap because is difficult to find ammunition for it! As you can see in this photos, it is a 8x60RS, .323 bullet diameter. The caliber was relatively common in Spain say forty years ago and was used for our driven hunt. I know at least another spanish hunter that reloads for it.
I got the rifle just two days ago and I am in the busy proccess of finding something to shoot with it! A friend of mine happens to have twenty rounds of 1920 vintage (Swiss fabrication), the bullet in the label is the 186 grains one. I will tell you about how it shoots as soon as I know. It is probably regulated for the 186 or the 196 bullet, but I´ll keep you informed.
Regarding brass, I know of a German manufacturer, Honeber, but it is not cheap at all (something in the 5-6€ each case). I have just asked my gunsmith for availability. In Europe, you can find Wolfgang Romey ammunition, fine but very expensive. Maybe this link is of better use for you:

http://www.cartouches-sologne.fr/catalogue.pdf

It is the catalogue of Sologne, a French ammunition manufacturer. They list 8x60RS in four different weights and brand of bullet. They are much cheaper than Honeber brass. They make the caliber for the Belguian market, where the 8x60 is "widely" used.
I wlii keep you informed in the forum or by PM.

Antonio Molins, Spain.