Sell it, don’t look back. If it is just sitting and you only pick it up once in a while, sigh, and put it back in the case, it’s over. Move it on. A custom, one off bass, ordered new, is always a money pit. You think you know what you want, but it just doesn’t turn out to fit well.
Six string basses have a limited market. Lots of six string owners with case queens that don’t get played. Not that many dedicated six string players.
There’s a flood tide of used basses out there. Do some research, buy at a decent price and if it doesn’t fit, you can sell it with little or no loss. I call it “catch and release”. Works for pedals, amps, basses, whatever.
But set a limit, or stuff will pile up. If I’m not using something on a regular basis, off it goes. Soon you’ll have a PayPal slush fund.
Getting started on selling is the hard part, once you get rolling, it’s liberating and the cash starts to pile up.