Hi Dozey
I've been using a 300mm long sharpening stone as a leveler, works OK but I'm sure the right tool would do it better. For logo's people tend to use decal paper in a printer mostly if doing it themselves. So far I've used auto acrylic and tru- oil, both have given good results.
Test fit it to the body and make sure your tuners fit the holes before starting, nothing worse than scratching a finish trying to fit things.