Checkered bezel as seen on rare Zodiac Sea Wolf and Seiko 6106 (http://forums.watchuseek.com/f281/collectors-guide-seiko-rally-sport-divers-194147.html).
Who was first in that design? Both models were issued somewhere early 1970th as I understand.

That's a really good question that I would like the answer to also!

Sorry, I cannot eve spell Sicko right and I know nothing about them. That is a mid-70's model though.

As a side note, and I am not slamming anyone, I never could understand why it mattered which company did what first. Once something sells then every other company follows suit. e.g. This craze for big assed watches that has leasted over a decade now...