Ranger44,
1. Check the lug bearing to the receiver bearing surfaces using prussian blue, if the contact is 80 percent on both lugs leave well enough alone.
2. The primary barrel bearing surface for the original Mausers was the inside collar in the receiver, not the front of the receiver. Interesting most of the military mausers have tighter tolerances and require less work with the receiver threads than many modern actions.
Due to the fact that the early Mausers are made of the steels equal to 1035 are only case hardened, lapping the bolt lugs in can remove enough of the case to require that the receiver and bolt be reheat treated. The case is normally 5-15 thousanths only. Removing too much will cause the lugs to set back into the receiver.
Do not automatically lap in the lugs on case hardened actions, this includes the high number double heat treated Springfields, matter of if the fit is checked as in 1 above, very few actions will need the lugs lapped in. This is unnecessary in most cases and a way for the gunsmith to make more money for charging for basically doing nothing.