Sure thing, Eric.
A couple years ago, I helped someone with their US one sheet for the movie, The Enforcer from 1976. The poster was folded and printed on glossy stock (just like yours is). Aside from the fold lines, it was in very good condition. The poster was sent to me, and I met with Mario to explain what was to be done to the poster, which was really nothing more than backing it, and getting rid of the fold lines, as one cross fold went right thru the face of Clint Eastwood. That made it a bit distracting to look at.
Needless to say, when the poster was dropped off a short time later, it looked incredible. And the fact that it was printed on glossy paper didnt make it any more risky to Mario than any other posters he had worked on, up to that point. The backing process did nothing to affect the appearance or gloss of the paper at all.