Your replies are very appreciated. I don't possess carpentry skills unfortunately, so I wouldn't be up to modifying my dear dear bass(I shaging love this Warwick, it's not perfect, but I love it, no way would I risk anything happening to it) I'm in talks with a luthier at the moment and I'm ironing out everything that I've liked about basses(3 band eq, thin neck, easy access electrics compartment, adjustable nut etc) and dislikes (bad access to upper frets, too big a gap from strings to body for double thumb etc). He actually said a ramp from the neck to the body is what most bassists have who use double thumb, and I then noticed it, once he said it. Mad how I never did notice, its looking like I got the right guy for the job here is a quick spec list if anyone is interested.
24 frets
Basslines all the way. A hot stack jazz with a series and single coil switch (to act like a humbucker of sorts) at the pridge a precision pickup centerband another J pickup at the neck. Aguilar obp-3 pre amp with 3 band eq and a push pull for active passive.
Body wood to be decided(asked for afzelia body with blackwood burl, but will work around if it can't be sourced here)
Thin maple neck with birdseye ebony fingerboard.
But most importantly, I worked out every thing I disliked about a bass ever in this bass build, and corrected it. Super low action achievable, a wide variety of tones, a punchy sound with lots of presence. Time will tell if I go this route, but I feel its only a matter of time. Chris Larkin is the guy and he's supposed to be a brilliant luthier. Nothing but good things, so I look forward to seeing how this goes.