Any scope suitable for the .308 WIN class of rounds will be good for the 7.5mm Swiss (and that means just about all of them).
A friend of mine got one of the K31s when they first came in, and were still dirt cheap. The scope mount he got cost more than the rifle (around $70 at the time). Don't know who made it (I thought it was swiss) but it takes regular 1-inch tube diameter scopes/rings. It is mounted on what I always think of as the "wong" side of the rifle, though.
