FWIW if your goal is simply to have a scoped M-N and not necessarily a replica sniper rifle, there are a few companies that make "scout rifle" scope mounts that replace the factory rear sight and with a mount for a Western-style long-eye-relief (eg. pistol) scope. This is by far
the least destructive way to mount a scope on these rifles.
Here's a link:
(FWIW I'm not necessarily endorsing S&K's products, as I've never used one of their mounts.)