those fitted to the 6119, 6106, 6105 etc) and hoping that they deliver the same power as the correct 6139 part, or trying a Generale Ressorts replacement of the correct dimensions. Assembly follows in reverse order to disassembly, starting with the setting mechanism, then over to the centre wheel and its bridge, the barrel, centre chrono wheel and third wheel followed by the barrel and train wheel bridge.
The chronograph mechanism comes together next starting with the L-shaped intermediate minute recording wheel holder, whose job it is to sit over the two jeweled settings on the train wheel bridge that serve the escape and third wheels and to provide the lower setting for the intermediate recording wheel.
With simpler designs, you can work around issues thrown up by slap dash servicing but a chronograph provides many more opportunities for the cack of hand to exercise their talents in ways that prove more challenging to correct.
And greens, deep turquoise, shimmering bluebottle greens.
Take all of this, add a dash of Japanese quirk, and we dial up the Seiko 6139-7060.
The consistent features of the early ‘70’s were boldness, colour and extravagant design flourishes and these elements seem to have provided a deal of inspiration in watch design too, particularly those conceived in the first half of the decade.
Acid yellows, burnt and vibrant oranges and dazzling blues all featured.
While we might look back in horror at some elements of this period, for many of my generation, the 1970’s were arguably the best decade of all for music.
In design more generally it was a mixed bag: the decade that gave birth to the Austin Allegro and Morris Marina was also the decade that produced the Lamborghini Countach and Lancia Stratos.
Nevertheless, in common with many of the mainstream Seiko movements of the time, it has proved to be remarkably robust yet it is this robustness that can be blamed for some of the difficulties these movements present when reviving them.
That may sound like an odd statement, but longevity, even in robust designs, results in wear and with the youngest examples now at least 40 years old, most of these watches will have had multiple services, not all of which executed by competent watchmakers.
The mainspring presents a slight difficulty in that original replacements are almost impossible to source.
The choice then is limited to recycling a spring from a junk 6139; finding a regular 61 series mainspring (i.e.
week in the UK album chart whilst Wings tussled with The Carpenters for the number 1 slot.