Guess what, went to Yau Ma Tei and Mong Kok again today and picked up something vintage and quite special, to my surprise. I found this vintage piece of promotional vinyl, around the size of a mouse pad, for the Headmasters series. It is date stamped "1987". On the front, it has an anime like drawing of the key Headmaster characters. On the back, it shows pictures of the 1987 Headmaster toys, including Sixshot and some Beastformers. Very interesting piece.
Also picked up Ghost Starscream (Henkei version) just for fun.