The C-5 vacuform in 1/72 was originally done by ID Models. Delta reissued the kit under their Delvac label. They also have Delta Decals and I think the host company is Delta Aviation Publishing. Can't find a web site for any of them though. The data I have is from Scale Aviation Modeler International, Jan 2001 so no idea what the availability of this kit is.
Paul built the original ID models kit (remember that from the article). I have one of the old Otaki kits in 1/44. Want to open it up and put some interior in it, maybe a few Chinooks or Apaches for a payload. Might give me a shot at that 1/144 category