j-shew
For the money you would spend to change calibers, you could get a full reloading setup and tailor your ammo to your gun.
It's really easy and doesn't take too long. I have been reloading the 8x57 for 10 years, lots of stuff out there to make your mauser shine.
I have three, 2-Yugo's and a German, reloading is the only way I can afford to shoot those babies.
If you still want to change calibers midway has Adams & Bennett (Green Mountain) sporter barrels under 100 bucks in 7x57,
then you need go-no/go gauges, an action wrench, a barrel vise, etc... it sounds overwhelming but it's not too bad, research is your friend.
As for Boyd's stocks I have two, and love them, one walnut and one laminated.
I bought both of them unfinished and finished them myself ( no checkering), each one has a Monte Carlo cheek piece design and distributes recoil nicely.
