[RodB]

The tuning capacitor blades should be cleaned. After 80 years they have acquired a film of gunk plus whatever has been in the air; dust, volcanic ash, etc. People have used everything from BrakeKlean to WD40 to using the dishwasher. First, you need to use a solvent to take off the crud, I use 91% alcohol with a long bristle brush. If you want to use WD40 then come back with the alcohol or electronics spray cleaner and wash off the WD40. Clean the capacitor with the gang open. After it dries you can use an ohmmeter to test each section for shorts. If a section has a coil across it, it will probably measure a few ohms and you'll have to unsolder the wire to that section. Don't forget to lubricate the bearings on both ends.

BTW Don't use BrakeKlean. Even after using it then a bath in the dishwasher it smelled putrid and had to spend a couple days in the garage to dry out.