If the handbrake cable is nylon lined then probably no lubricant otherwise some spray grease would not go amiss. A non drying sealant would seem the best for any joints that "work" - pretty much all of a Morgan I would say.

Richard

2018 Roadster 3.7
1966 Land Rover S2a 88
2024 Royal Enfield Guerrilla 450
1945 Guzzi Airone