Check put this link:

http://en.wikipedia.org/wiki/Jetfire#Toys

as a start.

When Hasbro had released all of the old takara moulds under a transformers banner, they wanted to get more product out there and sourced transforming robot designs from other companies in Japan. That included jetfire (and I think roadbuster and whirl) from takatoku, omega supreme from toybox (I think) and the deluxe insecticons from Bandai. In Japan, Bandai then absorbed Takatoku. When Takara re-imported the Transformers line to Japan, they ran into trouble when it came to any of these moulds that Bandai owned the rights to(deluxe insecticons, whirl, roadbuster, jetfire) and so couldn't market them in Japan so they got left out of the cartoon as well. My guess is that by the time hasbro was making these moulds, Bandai owned the rights and insisted theirs be the only stamp on the toy, or maybe it was too expensive to change the moulds.