Which sealer to use under Cellulose paint?

[Bod]

Grandson's guitar, he has made a wooden electric guitar, and intends to have it painted with cellulose paint, by a car bodyshop sprayer.
Any ideas what to seal the wood with?
I have Mylands Button polish to hand, or will a normal primer/undercoat for wood do?
Thanks
Bod

 

[CHJ]

I would have thought that a Cellulose Sanding Sealer would be the most compatible.