Internal Neck bracing for electric

Building my first 4 string electric now.
I have some old P-bass pickups - the poles almost line up.
Band-sawed a nice piece of African Mahogany into neck with headstock tilt.

The problem - can't use the same old "neck-through-box" mindset. The pickup protrudes so far into the box that I have to terminate it about 3 inches from ingress point.

Does anyone have any pics of internal bracing for something like this?.
Keeping in mind that I don't want to fill the entire box with a slab of wood.

thanks guys

PS - I brought one of the CBG's I build to the Cigar Store I get my boxes from. The guy wants me to build a few for him to sell in the store.
Problem is...
1) I'm having too much fun playing 'em..each one has flava
2) I think mass production would take the fun out of it.