I had read about the idea of the insignias being based on transformer heads but dismissed it as something fans had made up

I would really like to get it from the horse's mouth (and not mach kick's )
An interview from Bob Budiansky or Jim Shooter's (Marvel's Editor-in-Chief at the time) talking about how they came up with the concepts would be awesome. I wonder whether Bob borrowed/reworked some of editor Denis O'neil's ideas "that did not meet with Hasbro's expectations" to get to what part he played in the TF creation process all those years ago??

What ever you can dig up would be great paulbot
I had spoken to Griffin about this and he suggested (if possible) contacting someone like Jim Sorenson - One of the authors from the recent "Transformers 30th Anniversary Collection" (TF Comic Books), as he has no doubt done a lot of research including interviewing a lot of the author's and editors etc of the time that were involved.