Spirit based finish for '38 Kay

Knowledge , experience and assistance requested!

I am refinishing and updating a '38 C-1 Kay bass for a musician friend of mine. He requested that the varnish be spirit rather than oil based. Reasoning being that he thinks the bass will resonate better with the spirit finish than the oil. there is no convincing him otherwise, so with that as a given my problem is as follows. I have worked with oil based finishes on furniture and instruments for over 45 years but never had the opportunity to use spirit based finishes. He has supplied me with all the fixins' from Metropolitan Music in Vermont and the thinners smell like lacquer thinner. There is a (tinting stain? brown) to "bring out the grain" and Italian yellow, brown and French red spirit varnish. What should I seal the top with before spraying the varnishes. (It is my intention to use an air brush to do the entire bass.) The bass is in the white and he wants it to copy the old Kay style of sprayed C bouts etc. which should pose no problem with facility with the air brush. The attractive completion of this project is several fold, doing an attractive durable finish for a friend, and it will net me the last bucks I need to send my Juzek to Professor Arnold for a complete restoration. All assistance will be appreciated. Thanks,
Jim

 

Thanks a ton Mike. It's your claro walnut tailpiece that is going on the Kay and it matched the rosewood finger board perfectly. Also inlaid the old brass Kay emblem at a slant on the tail piece and it looks sweet with the brass Kluson tuners.
Thanks again,
Jim
Doc Mike's tail pieces rule the E string!
J.