Usually the copyright is different.
This includes diaclone tracks VS. GIG tracks. However there are exceptions... The black tracks from Finland sports the same tm as diaclone tracks since it was produced from the same mold before the GIG tracks.
IIRC without digging out my own toys, the diaclone police car has only Takara Japan on the waist, where the GIG version has a date added. You can always try checking:
http://www.tf-1.com/articles/eurous_frame.php?art=mbI use to have all this info in my head like the back of my hand, but since I've never really bought anything new for years..... I don't look at my collection much nor enter into these discussions which I've beaten half to death already.
I think Maz has more energy for it than I do now.
Most of the times the Joustra and GIG line will show similaritys to first run hasbro molds with the exception of having Hasbro in the copyright.
The one toy that comes to mind that didn't change until reaching the TF line would be Powered convoy. With the exception of the GIG red cab prime, the diaclone powered convoy, the GIG and Joustra powered convoy have the same mold and copyright. Mind you, i haven't had a GIG powered convoy to examine personally, I can only assume it to be the same from what I've seen on the web, and the fact that my Joustra is the same as the diaclone version. Besides, the DX set was made at the beginning of '85 and it is the same mold as the original from the line. In that set, molds of mirage and sideswipe have already been updated to what was being used in the TF line in the US.
Thanks. -Himawari