Vintage Gibsons were Centralab not CTS.
I know fender too used centralab sometimes, but on all my 6 gibson basses (5 from the 60´s and 1 from the 70´s)
there is CTS pots. I don´t think I have ever seen centralab pots on 60´s gibson, and I downloaded lots of gut pictures
when I was bitten by the EB-3 bug.
Got myself a ´66 SG last summer, CTS pots.
And yes, I did buy some chinese knobs for USA gibson pots, did not fit. They didn´t fit coarse knurled shafts either!
I usually end up buying knobs from philadelphia luthier tools (I know someone here is not too cheerful about this shop), because they have the correct metal top knobs with the small letters and they fit CTS. Good price too, compared to gibson knobs.