As far as I'm concerned you can do whatever you want to you guns. Its not like there are only 100 MN's in the world. There's been like 37 MILLION made
Originial shellac finish on my Izzy M44:
one can of brakleen and 10 minutes later:
I sanded it down taking care not to destroy any markings on it, ebony stained it multiple times, then put like 7 coats of wipe on poly on the stock. Its certainly not an original finish, but it made the gun look great.
The top piece was a different color and had a crack, so I took the opportunity to glue it together, sand it down, and stain match it to the rest of the stock.