hello, i just had new solid shaft pots put in my bass to replace the old split shaft pots i had and now my old knobs wont fit onto the new lager size shaft on the new pots. i have been to all my local music stores and no one has knobs to fit these new pots. (they are cts pots.) what is the shaft size on the larger pots? what size hole do the knobs need to have to fit the larger pots? thanks!