Excellent Work, really good painting.
If you add some Decals, you can varnish over them with normal polyurethane Varnish (wood varnish).
It would look like this...
Then spray 2-3 extreme light sprays DULLCOTE the Anti-Shine Varnish
and it will look like this...
The decals look ultra flat, like they were painted on!! No silvering and no problems.
When I was shown this technique I was blown away.. I use it on all my forces now.