This – my 1976 Seiko Bullhead Speedtimer.
Bought in a tax-free store in Japan for the princely sum of £40. Several shipboard colleagues either had this model or the Seiko Pogue.
It has the less common bracelet which also has spring-loaded clasp for a comfortable fit.
It’s still in pretty good condition as I went on to buy and wear a Seiko Sports 100, and the Bullhead didn’t see so much daylight after that.