As the last of the Vintage Grand Seiko series, the range of the 56GS series is second only to the 61GS with regards to the diversity of the watches produced. Whilst utilizing only three different movements - there are no “special” or “VFA” examples in this series - but there are 35 different models in the series produced from 1970 until 1974. One can find them in the catalogues of 1971 V2, 1972, 1973 V1, 1973 V2, 1974 V1, 1974 V2, 1975 V1 and 1975 V2.
The three movements mentioned were the no-date 5641A, the 5645A with date and the day-date 5646A, making this the only series with all three complication versions. Moreover, for the first time, an element of automation was introduced into the production line, and the beat of the movement was set at 28,800bph. The precision level may have suffered as a result of this transition, as a decrease in movement speed will do, but the reliability level on the other hand increased. Some people even consider the 28,800 bph to be the best speed for a watch movement with its balance of maintenance, reliability and precision. As these movements were mass produced, it is easy to get maintenance parts for the 56GS even now, 40 years after its production, making it the most reliable of all the Grand Seiko models produced in the past. Of course, a slightly less finely tuned caliber 56 movement was also used in the King Seiko 56 series and the Lord-matics 5606.
Whilst there is a large variety of case designs utilized in this range, unlike 61GS series, there is consistency in design and associated numbering of the cases used across the different movements.
Adhering strongly to the “Grammar of Design” rules, the -7010 and -7011 watches are almost certainly the most solid vintage Grand Seikos that you see on the market today. It is believed that the difference between the two cases is simply a move from marking the cases as being “waterproof”, to “water resistant”, but this remains to be confirmed. It is not consistent however with the 5646 models seen, where both -7010 and -7011 references are marked as being “Water Resistant”.
Due to the catalogues not detailing the last digit of the 8-digit movement-case reference number, it is not clear exactly when the change-over from the -7010 references to the -7011 references occurred.
There were many -7000 cases available for the 5645/6 movement and dials varied, For the -7010 the plentiful silver, the more uncommon white, the black and the navy. Gold cap models existed too. There was the 5646-7020, a striking watch featuring a case similar to that found on the 61GS VFA’s; a pillowcase model with tall indices, a polished case with a central fold line and only in a green dial. There was the 5646-7030, with its sand-textured dial and its unique lug width of just 17mm. And, rounding out the set of cases only available with the 5646 day-date movement, is the 5646-7040, unique amongst all vintage Grand Seikos in using applied, Breguet-type Arabic numerals on the dial (possibly the inspiration for the modern-day Wako limited editions).
The first appearance of the 564x-7010/1 in the 1972 catalogue shows the 5646 on a bracelet – the 5645 is only shown on a strap. However, The XQB 011 is listed as the bracelet for the 5645-7010/1 and the 5646-7010/1.
But as can be seen from the main Seiko catalogue shot for the 5645-7010, a completely different bracelet is shown for the watch...
In the 1973 catalogue, we see both the 5645 and the 5646 on bracelets, and both are shown on the same bracelet as that in the photo of the 5645. The reference number for the bracelet shown on both watches in the 1973 catalogue is XQB 070.
Thus, it would appear that at some time between 1972 and 1973, Grand Seiko swapped out the XQB 011 bracelet for the XQB 070. Whether or not the former was ever available at retail mounted on the 5645-7010/1 is probably impossible to determine, although clearly it was marketed as an after-purchase option.
Category Grand Seiko