I have a scan of the 1/24 scale Airfix Harrier kit decals, if you want it for reference.
I made my artwork using the scanned sheet and OpenOfficeOrg 'DRAW' so the graphics are in a vector format. However, the 'odt' native OOO format is apparently not entirely compatible with PhotoShop, but there is a way to troubleshoot it so a clean 'import' can be done. I did this with Mark Tutton at Starfighter Decals, just can't recall the specifics...
Again, let me know if you want any of these work products! ;^)
Regards, Robert