
In the deep dark corner of my parts vault I found a 520H movement. It’s rusty, but the base plate will clean up and the lower shock setting and jewel are in good condition.
I strip down the donor base plate and put it in the ultra sonic bath for a few rounds before drying it and putting it in the cleaning machine.
Base plate cleaned up and I have sourced a NOS balance. After spending a lot of time on the old balance, it was still too deformed to use.
Great performer!