It may require water to work. Kinda like an activator.
POR-15 metal coating is a really nice product. If one doesn't agree, paint some on a bare metal piece, allow to dry, then try to sandblast off. TOUGH stuff.
What I'm seeing is 50 year old built model cars that have most (if not all) parts (mostly still attached to subject) and decals that are well placed and are snugly stuck to body.
Looks like top-notch work to me......