Mags....try a pin, a needle or the point of a sharp knife, and prick the silvered area, apply some decal solution with a small brush and it should get in under the decal and help to clear up the silvering keep a tissue handy to quickly soak up any excess decal solution so it doesn't affect your finish, if it does simply recoat it later.
test out a small spot first to see if it will do the job ...and do small sections at a time, hope this solves your problem.
....and good job so far mate!!!