Just to muddy the waters, I bought an 1893 a few years ago with the sole intention of restoration. I guess I have a touch of OCD when it comes to guns - I like to see 'em all prettied up. If it were inherited, and the use were from a family member, that's one thing. But I personally have no attachment to someone else's use / abuse.
The 1893 I picked up had no case colors showing, maybe 40% blue left, rust pits and dings on the bbl, and well used furniture. When I got done with it, it's absolutely gorgeous. I paid 850, put another 600 or so in it for a new chunck of walnut, and Turnbull to case and rust blue after I did the metal prep. So for a little under 1500 and a healthy dose of elbow grease, I have a Marlin in a condition that I could never afford to buy if original. Did I kill collector value? Yup. But at 850, it wasn't high on the collector list anyway. It was as standard as it could be - no special order features at all. I just gave it another hundred years lease on life.
It all boils down to what you want. If you like 'em in original condition, no matter how bad, then leave it alone. Nothing more fun than holding a 110 year old rifle in your hands while trying to imagine just how it got in the shape it. But if your like me, and like one with a little bling, and can't afford original bling, then fix 'er up.