1953 336RC rifling

Maincoat was just about right on. However I'd add that if the cosmetics will clean up pretty well with oil and steel wool and the stock isn't cracked needing major repair, I wouldn't hesitate to push a bit on the price. It's hard to say how far without a hands on evaluation, and local market vary widely.
Early Marlin stocks clean up beatifully with some "furniture restorer"and steel wool followed with a couple of thinned coats of satin tongue oil or satin spar varnish or satin polyurethane. Normally no staining is not needed, as the wood is plenty dark already.
If the mechanics are flawless and the metal was fine and the stock really ugly, I could go $300, because I know what lurks within: materials, workmanship, and accuracy that new guns cannot match, plus an aged patina showing the experience of time. my go-to deer and pig gun is a '49 carbine. My best buy of late was a pristine box perfect 1947 36 ADL for $380. This specimen could have easily been priced $100 more by folks who know and appreciate old Marlins. Many of my others now appear as nice, but were bought as beaters, a couple with shattered stocks but oh-so-nice wood and metal. They're real lookers now.
My guess is that with a little elbow grease your 50's beater could be beautiful too.