Decided to use a Mauser.... there isn't a pretty rifle hiding anywhere in a M-N :-)
buff
I think you made the right choice, as you were indicating that you wanted to change the caliber as well.
While in some countries there are supplies to conver MN's from 7.62x54R to other calibers, such parts seem to be very limited and gunsmiths unwilling to do so in the US for modest costs.
Likewise, the availability of after-market barrels, stocks, triggers, bolts, alternate safeties, sights, scope mounts, etc. for mausers is huge compared to that for MN's.
Having said that I like my MN 1891/30 1939 Tula and wouldn't trade it nor would I seriously modify it because of the history it was part of.
Good luck on your mauser project.