Old,
You should not try to do the "polishing" yourself, you obviously (no insult intended) have no idea of how to go about it.
Relative to firearms polishing, there are two types: external to look pretty, and internal to decrease friction and smooth up the interface between parts that slide across each other.
Flitz & a buffing wheel....
That's for the outside.
Lapping compound has some use in firearms, but I would not consider it on a Marlin action.
Polishing of internal parts is typically done with fine abrasive stones, and done slowly so as not to remove too much material, alter critical dimensions, or round off square corners & turn straight lines into waves.
Very fine abrasive cloth has its uses, occasionally a fine grit paper. But- you need to know where & when they're indicated.
Do not take anything out of that gun & let it near a buffing wheel!
If you're not particularly mechanically inclined, which includes being able to look at the relationship between the various parts and do some troubleshooting analysis, and don't know much about how the Marlin operates, YOU SHOULD NOT TRY TO FIDDLE WITH IT!
This is one of those cases where if you have to ask, you probably should have a pro look at any problems that arise.
There's nothing wrong or embarrassing about not understanding the Marlin guts, the embarrassment would attach later on when you come back to start a "OK, Took The Buffing Wheel To Everything Inside The Gun, Now Nothing Runs Right" post.
Denis