We found 3 main types of the Stagg logo, with slightly different colors/materials for each group:
Type 1 (decal):
This seems to be the oldest, but it was probably mantained through the years, since it appears on many "lawsuit-era" instruments
Type 2 (decal)
Mostly seen of "Fender" headstocks, it has the same shape of Type 3, either with silver or gold contour. Note the ® mark.
Type 3 (inlay):
Elegant mother-of-pearl inlay, typical of the mid-70s and early 80s
Type 3b (inlay):
As we noted elsewhere, this more "spaced" inlay could be the latest version, enabling to date the instruments as the late series produced (1981-82?)
Type 4 (on Rick Bass only):
Only to be seen on the Rickenbacker Bass, the graphics has no similarities to the others, in order to reproduce the "inspiration" of the original