Where can I download the C07.121 movement decomposition diagram? What is the reason why the movement of the watch is particularly low after the watch is cleaned? Do the plastic parts inside the movement need to be cleaned?
Some updates, I measured the mainspring barrel of a 6498 and it's 16mm. I also tried loading a 10mm mainspring on an undersized winder, it did not load fully. So I answered my own question hehe. thanks.
This is the progress so far. The first image is the ebay seller's pic and the description was "Does not start, maybe battery but unable to confirm". In reality, it wouldn't wind, wouldn't set and the scratched up crystal looked even worse in real life (and the second hand had fallen off in the post), but I figured it had to be the twin of the one I already had, and therefore was well worth the 0.99p I bid.
Thanks for the correction regarding the movement. You are spot on with the fiddly calendar works, the first one I looked at, I launched those two springs more times than I care to mention, however forewarned is forearmed, so this one came as no surprise, and I even remembered which way round everything went without having to dig out my pictures of the first teardown. If you are aware of the issues and take care to do things very gently, the calendar works go back together reasonably easily. I did mange to gocha myself with the keyless works by pulling the crown out with the stem in the wrong position, but I knew I had been an idiot the moment I did it, so I only managed to indulge in that one screwup.
The watch is running well, but I haven't attempted to adjust it yet. Beat error is around .1 to .3ms and it kept up a good pace, within 20 seconds or so over the course of the day even without me tinkering with it. I'll let the lubrication settle and do a bit more with it tomorrow. The amplitude is still a little low at around 240 fully wound, so there is scope for a little improvement in that too. The other one runs around 270, so there is no reason to think this wont. I have an almost complete spare movement, including a mainspring, etc.so if I need parts I have them.
That red and gold Poljot on your "About me" page is a cracker, as are the others in your collection.