Ben,
As usual, Bill has explained things in a completely thorough manner and left little out, so that all I can do is echo his words. And he's 100% correct in that my "crusade" if you will against gloss coats is because I "ass-ume" (with all its unintended resultant side effects ...) that you are using acrylics--which, correct me if I'm wrong, but you DID indeed use acrylics in this build, yes?
There are guys who will still tell you to use gloss or "protectant" coats over acrylics, but I like to think that in my 20+ years of modeling that I have proven that it doesn't specifically NEED --and I emphasize "need"--to be done. I have put decals on over flat paints with zero bubblage; I have done washes and some of the most extreme weathering over flat acrylics, and cannot ever remember having paint lift or degrade.
But I HAVE seen models yellow from clear lacquer coats--and have also used clear coats in the past where I've seen tiny details literally absorbed into the coat, and that is my reason for such vigorous denunciation of what I feel is an old modeling canard. EXCEPT, of course, if you use enamels, like Bill. IN that case, you definitely have to "protect" your finish, as enamels take weeks to properly "gas out:. That's one of the reasons that they've somewhat fallen out of favor with car guys--you can now finish a car model in less than 6 weeks from painting by using fast-curing lacquer coats. In nay case, I would suggest to you that in the future when you gloss a model, do your decals and THEN "flat" it right afterward so that you can have a flat finish to weather over. You'll be able to get a clearer vision of what your weathering results are actually doing to the finish without all the shine, because light plays differently off of shin finishes than it does on the flat ones, and that affects your perception of what's going on. When I tried weathering over a gloss finish way in the past, I didn't like the "surprise" that I got when I flat-coated it, because the increased refraction of light coming off the finish sometimes wouldn't give me an accurate reading beforehand and I'd really see that in the finish when it got its final flatcoat.. In fact, I don't know how Bill gets his consistently-great results every time, but he does! Respect for Bill!.
I apologize if I was harsh, Ben. I'm running on jetlag here, having just arrived in Spain on yet another business trip and may not have considered my tone, I hope you know that I wouldn't let you down, buddy! I've been watching your builds steadily improve and you're coming a long way, and what's more, you've got the guts to try new things and to risk making mistakes---and that's a huge plus for your potential! I just want you to succeed so bad, and then get frustrated when I hear that you come up against another wall!
This turned out great in the end. A twisty, tortured road to get it here, but again--you're learning. It's great to hear that you'll be trying things differently;y on the new upcoming StuG. I'll be watching that one as much as I'm able to.