Improving a pre-modded Gibson EB0?
 

I recently inherited a friend's old 1968 EB0 bass. He used it some in the early '70's but has played it very little since, so he gave it to me. Gratuitous pic provided...

Somewhere before he acquired it in 1974 it had been modded with a single coil bridge p/u (looks kinda like a J-pup without a cover but I really don't know for sure) and a simple A/B toggle switch with no center position.

I can EQ a decent tone for the bridge p/u, but then the mudbucker is waaaay too bassy when soloed. The opposite is also true. When the mudbucker is EQ'd as good as I can get it then the bridge p/u is too trebly.

I want to replace the toggle switch with a pot. I could go either V/V/T, V/T/T (the volume levels are fairly close), or V/V/T/T with a stacked pot. Looking for input as to which option is most logical. Thanks in advance for any and all assistance.