Hello,
Thank you for the information. The listing doesn't state a calibre, or any information other than 'mauser M 1871'.....
From the pictures this rifle doesn't appear to bear any military proof marks, nor is it one of the known suppliers.
I can't find any information relating to the rifle, if you could I would be very interested to know more. Not sure if I will buy the rifle or not, certainly it would be an interesting and unusual example to own