Hey mate...as I can see on the pics, it's the different paint material ...better says the material from different manufacturers is the problem. Always stay with one manufacturer. And the next tip is...Do not paint too "full"...it's a bit tricky to explain this in english
I mean, if you paint the laque material too much in one working process, then arise such wrinkle formations.
Please also make sure that the first paint material is well dried.
Sry mate...I can't better explain this
....something like that can have different factors....of these three factors may have been one of them.
A question ...why did you not repaint the khaki paint?
Btw...good choice with the Davin Felth helmet...I like this too. My Sandtrooper is also the Desert Sergeant- Version
Here's mine--->>
Furthermore much fun with your build of your costume
Cheers...