Hi Erik,
A very nice Hellcat, just a couple of things. it looks like the port side roundel fought back
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sometimes, with a large decal, it can get difficult to move them around. This is because of the greater surface tension on the large ones. If like, on the port side roundel, you push up the edges, and they wont lay back down and leave a ridge, you could remove it by light sanding (when the decal is dry) and touch up with paint. If there is no ridge, but the decal is distorted, simply touch in with paint. The other large roundels look perfect. It's unfurtunate about the silvering on the "145" did you use a gloss coat?
I agree with Henk about a dark wash on the engine, it would make it look more realistic.
Your undercarriage looks a little "toed in", it's not always easy to get the undercarriage lined up, but it is as important as the wings and tail planes. If they don't want to line up then a little trimming of the lugs or slots maybe necessary. It's also important that the wheels are straight, front to rear, as well, there doesn't appear to be a problem on that score, well done.
One thing about tyres, painting them dark grey rather than black is good and the side walls, in general, will be cleaner than the tread. I useually dry brush the tread with 2 or 3 shades of earth colours, or a lighter grey, if the aircraft is used off a hard surface.
I have to agree about the exhaust stains, they were quite prominant on Hellcats. I'll post a couple of pics of my Hellcat, on your post in the aircraft forum, to give you some idea of what it, may have, looked like.
One other thing you might consider is the antenna wire.
A very nice Hellcat, one to be proud of
Good luck with your Boston, do post pics.
Mal