If you do it yourself... make sure you have a good set of GUNSMITHS SCREWDRIVERS.
I have taken a few pre war Winchesters apart... about the only part that causes real trouble is the magazine tube. Those need to be swabbed out every 80 years or so. I bet your 50's version could be cleaned well enough by cracking the action open and going after the innards with spray solvents, rags, old toothbrushes and fingers.
When I work on a Winchester lever that needs a little more attention... I pull the buttstock.. hose out the guts with a good solvent and blow it out with compressed air. Oil up the moving parts and go shooting.