I've given that some thought and might be another option. Its not something i would tackle myself. I've never actually changed anything on a bass. I like them as they are but this was a bargain, has a good neck and generally a nice lookng bass it would be a shame to sell it for buttons when a new set of passive pups would sort the bit that's bugging me.
Because i have several other basses this one isn't a priority and more a side project. The fact the pick ups are not set mid point creates another issue for it..
Dave