I didn't think it would take too long for this Kenyan Military Autavia ref: 73663 to be up on the board for discussion. Soon after receiving mine (with no military markings) I saw the ebay listing of the one shown by the OP. It was only the third sample I have seen including mine. These so called Shauntavias with Arabic numerals of amongst the scarcest of the 70's Autavia or any other Heuer from that period. They did not feature in any catalogue we know of and the numbers sighted for both two and three register examples are extremely low. I cannot offer much more than a picture of my examples and to add that my two register ref: 741.603 has an amazing high beat movement which I only discovered recently.

regards
Paul
www.heuerworld.com