Roger the wingtip lines definately go over the top of the wing. As for the middle stripe I've seen some 31st photos that definately show it going over the top. I've also seen some that make it hard to distinguish if the line went over and under. The D Models line was extremely close to the wing root itself.
I have found one photo of February and it definately has the line over the top. What strikes me as odd is even though it's in black and white the paint doesn't seem to be yellow. More like it was red instead.
The thing is though there is a P-51 painted in this scheme that Brooks himself has looked at. I would assume that if the paint was incorrect he'd have said something to the owners. You can find a replica of February on this
site.