Converting Harvey into a DMU

There is one problem with both of these procedures as the decals or clear labels only look good on light surfaces and white will turn out clear as printers don't seem to print it.

White decal paper for inkjet printers is easily available, so that's not an issue. remember that decals should always be applied to a gloss surface, not an issue with your DMU I imagine. A good clear gloss for a final coat over the decals and anything else is available in the form of Johnson's Klear tile varnish (in the US it's called Future). I've got enough to last several lifetimes, but see here for current availability.