The story:
Sometime last year I bought a package of 2 busted watches from a member who had bought them from the original owner. I received the SMP chrono without the bezel insert glued down, fitted with the bezel ring from the asian gmt (previous owner did a good job with that), and with a busted asian 7750 (pallet jewel gone so the watch was unwinding without being timed). The problems came from the poorly made crown and stem that had messed up the keyless works and eventually caused the internal damage to the movement. Also, the first owner had bent the original bezel ring trying to remove it to properly seat the insert, hence the bezel transplant. The insert is from the original rep to my knowledge, it just happed to have a perfect pearl.
So as I was trying to figure out how to fix the asian 7750, I found a cheap 17 jewel Valjoux 7750 on eBay and snapped it up. I tried to modify the center seconds hand to fit the larger post of the Swiss 7750, and in doing so destroyed the hand (setback #1). After shopping around, I finally ordered a gen hand from ofrei.
I tried fitting the face and hands to the movement to see how the timing on the watch was. I foolishly used the old faulty rep crown and stem and in doing so popped the keyless works of my new movement and stopped the watch cold (huge setback #2). You think I would have learned from what happened to the asian 7750. So at that point I took a few months off to improve my watchmaking skills, cause this movement was gonna need some serious surgery.
After collecting all the necessary tools and doing some learnin’, I decided to tackle the nasty 7750. Thanks to the ETA charts, it made taking it apart and back together look easy. Thankfully I could leave the hugely complicated side alone and focus on the bottom and calendar plates. By the time I was through, I had broken down and put back together the calendar and bottom plates 5 times before figuring out what was wrong. The pressure from the stem had popped the hacking lever out of position and jammed it into the rest of the keyless works. This also stopped the whole movement. It took some force (not what you want to be doing to something connected to the balance) to dislodge the hacking lever and put the keyless works back into position. I also oiled up everything I could get at according to the ETA chart.
Feeling awesome, I put everything back together got the face and hands on and got her going. Unfortunately the 12 hour chrono hand was constantly running (setback #...I lost count). A careful read of Ziggy’s 7750 picture tutorial showed me that I hadn’t kept tension on one tiny part with one ridiculously small and difficult to work with spring. After stripping down, cleaning, and reoiling everything again….I finally was in business.
All I had left was to solve the crown problem. I decided to shorten the stem because I think that may have been causing most of tension. That way I could have the crown not screwed down and it would look halfway normal which avoids the problem of the weak spring in the rep crown. It worked like a charm, and actually I can screw the crown down all the way again with no problems if I wanted to.
There were also multiple polishings of the case and bracelet over that time. I could not be happier to be done with this project, and I will get to enjoying my new (old) SMP classic. Thanks for reading about my first real adventure in modding and watchmaking.
