LeftyBassist.com

I always thought these would make great fretless basses.
(The truss rod and fretboard issues are a dealbreaker for me... but it is fretless at third fret!)

https://www.ebay.com/itm/1982-Carvin-LB ... 890.l49292

I wonder what caused the cracked fingerboard: the truss rod issues, or possibly lack of maintenance? I know ebony can turn brittle if it isn't maintained properly with a regular touch of oil. Anyone with a woodworking background here who can chip in?

I have never seen, in all my years repairing instruments- including string basses -of which the better ones are are commonly fitted with ebony boards, THAT level of damage that was caused by any kind of 'natural' occurrence. It either took a fall, or some kind of heavy object hitting it to do that. That said- a truss rod that is over tightened by someone who doesn't know what they're doing, can do some major damage- anyone who repairs basses will tell you the issues with cracked boards at the nut on 70's bullet truss rod Jazz basses, and Rickenbacker basses with lifting boards, separations, and cracks.
That bass, would be a cool project for someone like myself- but frankly, I have other things to do- it would make a great project for someone with well above average woodworking skills to take on. The board should be removed, and a new rod installed. A good opportunity to totally restore and upgrade this instrument to a dual acting rod and maybe even graphite reinforcement. The issue for anyone buying it- is- do you have the knowledge, tools, time and money... can you actually do the work, and more importantly, what will be your 'return' on this investment? A lot of time and effort will be needed to put this back in playing condition. These early Carvins turn up now and then, for fairly reasonable prices, too. By the way, every one I've played, sounds killer.

To me that kind of serious crack in the neck seems like a serious force has hit that neck. Maybe it has been thrown off stage by someone? If you look closely at the headstock photo there is a crack there too?

Geez... considering the description of repairs needed, parts missing, and time involved by someone who knows how to restore this mess, the price should be @$25 to pay for his time, and the shipping cost, to ship it to someone who is willing to take it on...