Wedgie:
A significant part of the appeal of a commercial Oberndorf Mauser is the barrel taper, as noted in your initial posts. Without it, you lose the fabulous lines that define these classic rifles.

A 7mm or 8mm barrel will likely taper from 19 or 20 mm where the taper starts in front of the chamber, down to 14-and-a-bit mm at the muzzle. Front sight ramps consequently need a little bit of fiddling to fit properly.

And IMHO you won't want a mill-bastard front sight ramp! Pretty simple to just file-cut the ramp for ribbing or checkering.