Microscale/Superscale put out sheet #32-29. It has markings for 3 AH-1G's of D Co. 227th AHB as well as Hugh Mills' OH-6A "Miss Clawd" IV. The Cobras all feature nose art; "The Gremlin", "HULK", "Timujin Ship". The nose art appears to be accurate (I saw all three cobras in Vietnam as they were piloted by friends from flight school and we flew some combined ops). The serial numbers in the data blocks are legible and, unfortunately, inaccurate for all four aircraft.
I have the sheet, intact, but because of its age I would not use it without first applying a coat of Micro Superfilm. This is a liquid decal film which can be applied with a small flat brush. It will prevent old decals from splinterring into a gazzilion small pieces as soon as water makes contact with the sheet. The individual decals must be cut from the sheet after the film dries.
If you can't find this sheet anywhere contact me via e-mail and I could be convinced to part with it.