Thanks for the additional info concerning your Mauser (capitalized as speaking of the specific Oberndorf Factory product versus non-capitalized "generic" mauser pattern).
Read + visuals as seeming A-OK for Oberndorf Sporter apparent originality! Expecting a hinged floorplate and if not, possibly indicative of a military sporter Model "C", but that "WM" butt plate versus military plate also suggestive of "B" Model as correct.
The 8x57 presumptively correct actually into the early Twenties as Armistice melded into Versailles Treaty & sanctions a creature of early Twenties! About 1932 the "new Fascist Face of Fatherland" emerged. Abandoning the Treaty and returning to 8mm military chambering production, but fewer in commercial context due to strong rearming emphasis!
The first thing I look for in a Obie Sporter is the angular tear-shaped bolt handle. Can't distinguish that but 'assuming 'there'... Large "originality hurdle" past! Next, all matching numbers as more than just "icing" to collectors. It's the realm of - all original - the larger bucks formula.
The above suggestion to D&T for scope... Your rifle, your call! But also your responsibility for care and preservation of rifle as Obie "art" when intact. Oh yes, and depreciate value by perhaps 50%. Assuming whatever aperture sight, to be "swappable" back to original... Go for it. Otherwise back to 50% valuation possibly!
The absence of receiver ring nomenclature or factory pattern adornment is common and while such collector Viagra, absence no condemnation at all.
Whew~
Congraats!
Best!
John
