The Omega Seamaster chronographs from the 1970s took a sharp turn away from the more classic monochrome designs of the 1950s and ’60s to funkier looks with bolder cases and more colorful dial designs. The Seamaster shared this trend with the Speedmaster, which is typically thought to have started with the Speedmaster Mark III ref. ST 176.002. It featured a similar dial layout to today’s watch, with an inner tachymeter scale, a date window at three, registers – including a 24-hour AM/PM indicator – at six and nine o’clock, and an airplane tip on the central chronograph minutes hand. The ref. ST176.007 replaced the preceding ref. ST 176.001 in 1972 and remained in production until around 1976, a fairly short run. The reference was offered in a stainless steel case, a gold-plated case, or a full 18k gold case. The steel version was offered in two dial color variations, in blue and silver, while the gold-plated and full gold versions were offered in gold or brown dials. The case was produced by case manufacturer Ervin Piquerez SA (aka EPSA), famous for their water-tight dive watch cases issued to many Swiss watchmakers, including Jaeger-LeCoultre, Longines, and countless other prominent Swiss watch firms. What’s interesting is that some of the the Seamasters and the Speedmasters were fitted with the Omega caliber 1040, which was the brand’s first automatic chronograph movement. This workhorse movement was based on a movement produced by Lemania (caliber 1340), originally developed by Raoul-Henri Erard. The copper-colored movement had a frequency of 28,800 vph and came with a date and a 24-hour indicator.