I don't have a scope on my Mosin yet, but have been planning on doing it for awhile. I have no interest in a period-correct mount, so the two I have narrowed it down to are these:
jmeck scope mount - uses a steel band around the receiver, no metal work, minor inletting in the stock
or
Rock Solid Industries drill and tap mount - evidently it's "rock solid", but requires the drill and tap, of course.
Both have good reviews. I'm tempted to go the jmeck route so I can avoid the screw holes in the receiver if ever I were to remove the scope. Both of these mounts require turned do