I used Halford's clear car lacquer, dusted on in light coats. Just enough to seal the wood. It feels great if you like a satin finish. I believe building up more layers for a gloss finish involves polishing with an abrasive of some sort in between layers. Hardly experts corner, but y'know.. 
Btw, post some pics and tell us how you get on. I fancy putting a MM neck on my Jazz and I'd like to get your opinion.
Btw, post some pics and tell us how you get on. I fancy putting a MM neck on my Jazz and I'd like to get your opinion.