Originally Posted by dddd

Sometimes some silicone/Teflon-based lube will nicely restore the old cabling's performance. Sometimes not.

Oiling the shift levers, any light oil that penetrates readily should work, just avoid lubes like WD40 which are like 90% solvent and will evaporate away.

Schwinn used a lot of French-made Maillard hubs in their wheels during the '80's, unimpressive quality and always installed with bearings adjusted over-tight (which inevitably led to very early bearing-pitting failure).
Hub bearings are lubed with grease, though often I just adjust the bearings and then oil them without disassembly, for my first few hundreds of miles of use.