I’ve previously featured a 62mas where I said it’s one of my favourite vintage Japanese dive watches, so there’s no apologies for featuring another. This example came in for a movement service and was in pretty good shape considering the age. The hands are missing because it came to me via James Hyman who’d already relumed the dial and handset, there’s no point putting the hands back on if they’re coming straight off again!

With the caseback removed the movement looks in reasonable shape with no obvious signs of butchery!

During the strip down it continued to look good, just dried lubricants visible, these are the little black dots here and there, and are actually a mixture of dry lubricant and tiny particles of metal! Heres a few pictures of what you can typically expect to see in a movement that hasn’t been serviced for a good few years.

It had even migrated to the pallet fork. It doesn’t take much to stop a mechanical movement and I’m sure if this wasn’t already stopping it wouldn’t be long before it id.

With the movement fully stripped it was ready for a trip through the cleaning machine, prior to inspection.

Whilst the components were cleaning I turned my attention to the case. The lume had dropped out of the insert and the bezel was seized solid so there was a couple of jobs there to start with.

With the bezel finally removed it was hardly surprising it was seized! You can see these earlier bezels (like the 6105-8000 one) are held in place with a wire spring as opposed to an o-ring.

With the case components ultrasonically cleaned I thought the crystal looked a bit worse for wear. As there was no cracking and it looks like the original crystal I decided to polish the worst of the scratching off as opposed to replacing it.

Take a deep breath and attack the crystal with some 2400 grit emery paper, sanding across the direction of the worst scratches. As the marks disappear use finer and finer grit paper…

….until you can use some paste to buff it up. Not perfect but a huge improvement, and it’s original!

The components were inspected and the rebuild begins with the mainspring, as usual!

The motion work coming together.

The autowind bridge back on and ticking away nicely.

The usual problem with these calibres is a shot clutch and this one was no exception. This component is engaged with the date corrector when the watches crown is pulled out, and it (and the date corrector) tend to wear badly.

You can see where the teeth have visibly worn down in this shot. These components are very difficult to source these days, this NOS one came all the way from Australia.

When the clutch is shot the date corrector is normally worn too, but this one was actually in pretty good shape so it was reused.

The keyless work reassembled.

Ready for the top plate to be fitted.

The relumed dial and hands refitted.

The movement is recased in this shot.

The remnants of the old lume was removed from the bezel and a tiny dot was mixed to replace it.

Original 62mas bezel insert pips tend turn this browny colour after nearly 50 years, so now it still has the correct vintage look. It’s turned out beautifully – have I mentioned how much I like these 62mas’s?

And finally what a cracking caseback, beautifully sharp. These ones from 1967 seem to survive better than the earlier ones for some reason.