[PeterD]

- Overlay1 = null.tga
- Overlay2 = null.tga
- Overlay3 = null.tga
- Overlay4 = null.tga

- Overlay5 = xxx.tga (markings)
- Overlay6 = xxx.tga (markings)
- Overlay7 = xxx.tga (markings)
- Overlay8 = hakenfake.tga.tga (markings) :-P

- OverlayD1o = damage1o.tga
- OverlayD1p = damage1p.tga
- OverlayD1q = damage1q.tga
- OverlayD2o = damage2o.tga
- OverlayD2p = damage2p.tga
- OverlayD2q = damage2q.tga

I think this depends a bit on a per-plane basis. Checking the P-80 (Multi1) these are my findings:
Overlay 1 and overlay 4 are "RS" and "A" for RAF markings, applied to the fuselage (right and left side)
Overlay 2 and overlay 3 are, again, "RS" and "A" for RAF markings, applied to the tail sides.
Overlay 7 is the main RAF roundel
Overlay 6 is the other RAF roundel (the one without yellow in it, just red and blue)
Overlay 5 is only present on the nose, so I guess it's just for USAAF/USN numbering

If you use overlay 2 and 3 for the fuselage and tail, you get repeated codes in other markings, ie:
01 01 for IJA markings
I haven't checked with overlay 1 and 4 but I suppose it is similar.

So basically I would separate it this way:

Right side:
From tail ----> to fuselage ---> to nose
(Overlay 3) ---> (roundel = overlay 7) ---> (overlay 4)
translates into:
(RS) (roundel) (A) [RAF]
--> (roundel) --> (01) [IJA]
--> (germany white "roundel") --> (triangle marking) [GER]
and so on

Left side:
From nose ---> to fuselage ---> to tail
(Overlay 1) ---> (roundel = overlay 7) ---> (overlay 2)
translates into:
RS (roundel) A [RAF]
--> (roundel) --> (01) [IJA]
(triangle marking) --> (germany white "roundel") --> [GER]
and so on


Not sure if that makes sense :S


Basically I think it has to use overlay 1,2,3 and 4 in order to have the german markings correctly placed for both sides, while the rest of the nations could in fact just use either overlay 1 and 4, or overlay 2 and 3