Warmouth's Gecko body pocket/neck heel shape is,
AFAIK, unique. No one else makes interchangable parts.
Moses' electric bass replacement neck website lists only Fender and Music Man/G&L, and Steinberger replacements, plus something referred to as a "Moses Custom" shape.
Moses, Status, or even Modulus might be persuaded to do a custom job, though, if you want a carbon-fiber necked Gecko. Hope you have enough money!