https://en.wikipedia.org/wiki/Cosmoline

dry cleaning solvents in 1941 were likely Varsol or Stoddard's Formula.

compare to trichloroethane<br /> https://hypothes.is/a/EyBIAFXAEe-AcP-Atlj_aQ

Note discontinuation of carbon tetrachloride<br /> https://hypothes.is/a/bfdi_I90Ee-OQLN0HpsE7Q

Most typewriter shops did not use alcohol as it was ineffective and contained water. Industrial alcohols contained keytones and acetones that will melt plastic and remove paint.

Solvents for typewriters used in repair shops: - White mineral spirits with a squeeze bottle. (Sometimes also called Varsol, Stoddard's Formula, and possibly Inhibisol) - Naphtha (aka lighter fluid; used in Zippo lighters, and frequently seen in Europe). PB B'laster is essentially pressurized naphtha in a can. - Auto carb and brake cleaners, usually pressurized in a can. These usually have acetone in them and will melt plastic. Will remove WD-40 if accidentally used on a typewriter.

For cleaning typeslugs, one can use naphtha or mineral spirits with a brass bristle brush.

For platen cleaning try mineral spirits or fedron.

Only oil the carriage rails for the bearings or trucks.

(This is all colloquial advice, albeit with experience, so check specific facts about what certain products contain.)

should find a better reference