When Seiko began development of their first core quartz diver, they didn’t have to look far for inspiration. In fact, the 6309 had only been in production for two years when the first 7548’s rolled off the production line in late 1978. Bearing more than a passing resemblance to the 6309-7290, the 7548-7000 shares an almost identical case, and the bezel, insert, crown, crystal retaining ring, and crystal are all interchangeable between both styles. And if architectural similarities were all there were, it would no doubt be a great watch by default. However, Seiko did as Seiko does, and quite literally built a quartz driven 6309 movement. With the case back removed, one look tells you all you need to know about early Seiko quartz movements. They were not plastic disposable machines to be quickly swapped out at the first sign of trouble, but beautifully, if not overly, engineered movements with jeweled pivots and precisely machined plates. This JDM variant from June of 1985 is the transitional and increasingly rare 7010 reference. Production was very short-lived, and it would mark the last of the 7548’s before the introduction of the 7C43 that same year. Though it would seem difficult to improve on the 7000, the 7010 gained another 50m in water resistance, and donned its 200m rating on the dial. At that depth, it now qualified as a professional diver, and that benchmark was noted on the dial as well. This improvement was due to an upgrade in case architecture, and one that would become standard on the follow up 7C references. Like the 6309 “Turtle” before it, the 7548-7000 utilized a snap down crystal retaining ring. The 7010 incorporated a more robust screw down retaining ring, and now all three points of entry were better defended from moisture intrusion. The dial is a spotless matte black with large luminous plots, and the hour and minute hands have been carried over from its predecessor. The second hand, however, is a black and white reverse “lollipop” with a large pip at the end of the tail. The bezel rotates smoothly with a firm click in either direction, and the insert shows moderate, even wear. The case is unpolished and its factory finishes are still clearly visible. The crown, case back, and crystal retainer screw down tightly with ample threading to protect the freshly serviced 7548. It offers independent quickset of both the day and date, hacking seconds, and with a fresh battery installed, it’s keeping perfect time. We’ve paired it with a Seiko Z-22 flat vent strap for a fit and finish very close to the original. Aside from its rarity and redesigned case, this reference is special for one more reason; “Queen” fans will know that guitarist Brian May made no secret of the fact that he picked up and began wearing a 7548-7000  while on tour for the first time in Japan. He quickly graduated to the 7010 once it arrived, and it was a fixture on his wrist both on and off the stage for decades. A rare JDM transitional reference with a Rock Legend endorsement makes this an easy addition to any roster.

Seiko Z-22 Flat Vent Black Composite Strap

Serviced- 5/26

Diameter- 42mm

Lugs- 22mm