Boyds makes many different styles to fit a mauser. They have some that need fitting then they also have what they call a VIP (virtual inlett part) stock that should require no inletting at all. If it does it should ve very minor. Walnut and laminated.
BOYDS SITE

As far as barrels go you can get barrels from brownells that are pre threaded and short chambered. All one would need to do is hand ream the chamber to set headspace and torque it on the receiver. This is still best left to a trained gunsmith.

Then you have the barrel blanks that bigcountry listed that would need to be threaded, cut and crowned, chamber reamed and torqued onto the receiver. This will be the more expensive rout but if done right will probably be a better shooter.