I have a '78 Gibson custom, has 250k pots, my '73 SG has 250k pots, allmy other gibsons prior to the 90's have 250k pots. The only with 500k pots is my '76 custom but it does not have original pots, they are recently replaced because it also had 250k pots.
250k pots make a guitar sound muddy and dark, this was the custom sound back then, thats why the standard's were more popular.
The only thing i can think off if they really are 500k pots is that the lack of use corroded the electronics and adds extra resistance to the path, which i have encountered sometimes. If this is the case, fumbling with the pots and jack some time will improve the sound a bit. Restoring it to full potential will take either redoing the electronics or restauration by a
good tech.
If this is true especially your bridge pickups will sound very thin and liveless, neck very muddy and bassy. What i would do is take it to a
good tech an have it checked first.
One advise, DONT give up on your pickups! I once tossed an 80's PAF because it sounded so thin i thought it was broken, later i found out the volume pot for the bridge was broken....... :oops:
The unpotted mules i have in my '76 (with 500k pots) are exactly what im looking for as a PAF addict, they sound very transparent and balanced and offer the smoothest PAF tone i have ever heard.
I would personally upgrade the R9 with Mules and restore the '74 custom, burstbuckers sound like sh/t (sorry)!
EDIT: Ok ive read you replaced the burstbuckers allready, never mind the....
