I agree the barrel is most likely original. Also agree the best way to be certain is a chamber cast.
The stock is most likely either a Fajen or a Bishop, and I'd lean towards Fajen, the pistol grip is very similar to Fajens, I have had.
Contrasting rosewood forend tip and pistol grip cap, this was not the "economy grade" stock.
The bolt handle has been "bent" (cut and rewelded), a scope safety has been installed, and the issue sights removed. I can't tell for certain from the pics if that is the original trigger, but it could well be. The original Mauser trigger can be turned into an excellent (sporting rifle) trigger fairly easily by people who know what they are doing. Some kept it two stage, some would make it a single stage trigger.
The bottom metal is all original, (matching #s), and its the only real step left unconverted. A "complete" sporter job would have replaced the original with a hinged floorplate version.
The triggerguard was often left in original condition to save a few buck, or because having a hinged floorplate simply wasn't important to the owner.
sometimes the triggerguard bow was slightly recontoured by the smith, sometimes not.
very nice rifle, classic sporter. congratulations!
