hmm....well CROSS is certainly the guy to ask, but he almost never posts here...perhaps you could track down his info and fire an email off to him.
Also, if I were going to build my very own Jazzmaster, this is what I'd do:
1. Buy the neck and body off ebay.
2. Make my own blueprints of the neck and body.
3. Build the neck and body
4. Sell the purchase from step 1 on ebay
5. Dance a jig cause I'm a genius
6. Have a beer. 😁