That confirms my thought. You see a Cross of grey wair mark specks right in that area.
Gmax does that too sometimes when working with double sided parts.
You may want to check that other poly that looks almost white in the S/S I posted. It's attached to the left side (facing it, right side of the Fuselage) of the Arrow.
No Rush, I can work on other portions of this skin while you're working on that. Lots of parts to paint in this skin. By far the most complex one I've tried to do.
:ernae: