Pat,
This from "The Broomhandle Pistol" by Erickson and Pate:
"After testing several unnumbered prototype pistols, Mauser commenced production in mid-1895. From known serial numbers, total production of these early Spurhammer pistols was but 50 and encompassed not only the ten and twenty shot variants, but also a few six shots."
I would say that the pistol that you have here is probably one of those few six shot models that are mentioned in the above book.
This book is 20 years out of print but it is listed here if you are interested:
http://www.alibris.com/search/search...*listing*title
SteveM