Internal Gear Hub maintenance help

Ive got an odd one.
its 1950s and a generator hub. no model number on it though!

it has an oil port but when i cracked it open was running on a very weighty grease (which was knackered and drying out), assumed these all ran on oil so put half a pint of sa30 (lawnmower oil) in there which promptly ran out all over the floor from both sides.
guess it was a grease hub after all? but running grease in there the frehub us rubbish and shifting either way is very slow and clumsy.

anyone any ideas?

If it's Sturmey it should run in oil. but you only want a little bit, not half a pint.
Most hubs I have stripped down were working badly because someone had packed them with grease. Once cleaned and given a few drops of oil all their problems went away