Craig,  The International Violin Company, Ltd., in Baltimore, Maryland,
carries oil and resin varnish in small quantities for doing string
instruments.  They are on-line, too: http://www.internationalviolin.com/ 

I don't have the recipe for the varnish anymore, but it wasn't a real
difficult varnish to cook up.  I found it in some old violin making
books many years ago when I rebuilt my first violin (my Mom wouldn't
let me cook it on her stove, though).

Due to California air quality regulations you may not even be able to
get it shipped in, but you could easily make it up.  I'll have to go
through my library of books to see if I still have the recipe; if I do,
I can post it sometime next week if someone else doesn't beat me to it.

Dan Armstrong - Armstrong Piano Tuning & Repair
Pine River, Minnesota