If I were to keep both of them would it be silly to put an upgraded optic with some magnification on one of them, so I could have some fun taking some longer shots. Or am I missing the point?
If you were to upgrade optics, I would look at replacing the rings as well; that way it would be easy to return the rifle to it's original condition if you ever wanted to sell it. Those old German scopes that are on there now are likely an odd size, so the rings wouldn't fit a 1" diameter scope in any case.
As far as magnification goes, I run a fixed 4x on my 7x57, but really, you can put whatever you want on it as long as the rings fit.