After cleaning and reassembling my Gilbert Parisian clock, the pendulum did not seem to be able to change the rate even though the pointer was moving when the rating knob was turned. After reading a thread started by imreman in 2012 I tried balancing it to see if turning the knob would change the balance point. I concluded that the lead bob inside was not moving up or down. I finally got the courage to open the case and discovered that the female threads in the lead bob are stripped. I can’t separate the threaded rod (inside the case) from the rating knob on the outside. I tried heat and a couple different penetrating fluids with no luck. The threaded rod does not seem to be any standard thread. It measures 32 threads per inch and major dia. 0.099 inch (about 2.52 mm). Any ideas how I can restore this pendulum’s functionality?