So the context is I've got it into my head to start collecting a number of the Star Wars LEGO Key Chains. As many are retired I've turned to BrickLink to assist my compulsion. I also recently read somewhere about how LEGO are almost religious about stamping each piece. Sure enough all the newer key chains I've picked up have the word LEGO stamped in the same location as the minifigs from sets.
Of the slightly older ones I've so far picked up Onaconda Farr 
and Scout Trooper 
and oddly they both don't have the word LEGO stamped in the same location or anywhere else on the keychain that I can see. Now they were two key chains from two completely different BrickLink sellers so this isn't meant as an accusation but I am curious. Were the older ones done differently and if anybody purchased a key chain directly from LEGO from around the same time as those do theirs also have none of the typical markings indicating it is LEGO like normal pieces and the new key chains do?
The ones from 2014, 15 & 17 all have LEGO stamped inside the foot while the ones from 2010 don't. I haven't found any good images that would tell me one way or another.
Thank you to whoever is able to continue my education of LEGO here :-)