I would keep it as is, Funky!
Yours appears to be an unmolested original? That is worth preserving, and adding different or as some call them upgraded pickups, pots, wire harness etc will suck all the character and charm out of it. Unless you have the ability and patience to fish the electronics in and out of a hollwbody guitar the time and labor won't be cheap and then you might not care for the change or changes. Also completely hollow guitars are very tricky to play at stage level especially with hotter pickups, Humbuckers, P-90's and all like to create body resonant feedback. There are better and easier guitars to swap stuff around with and you won't find many left like this. Besides I think it might be tough to find a direct fit replacement for those, so more added modifying- buggerin'.
Get a volt meter and check the ohms (impedance) of your pickups for a baseline idea to see where these are.