Non sticking decals

working on my last model I forgot to attach one part before trying to apply one decal. I decided to take it back to the non-adhesive paper, glue the missing part and apply it again. I found that the adhesive on the decal was gone! I need some ideas, please take into account that I’m working on a Chrome silver finished model (Mustang P51D).

two solutions I have used:

  1. dip the decal in a mix of water and PVA glue, then lay it on the model;
  2. lay the decal (onto the model) onto a fresh patch of Future.

Then secure with a coat of varnish (Future for instance, but others if you need a flat finish)