I recently overhauled this Seth Thomas and found that the bob is not original. The bob that is with the clock is a replacement and weighs just over 2 ounces. It runs ok but is a little erratic near the end of the spring wind. I tried one from a Seth Thomas 89 that weighed 5 ounces. The clock was very steady but too slow. I believe one in between these weight ranges will work. I know Timesavers and Merritts has them I just need to know which weight. I've included pictures of the clock and the movement. BTW, the movement pic was taken before it was overhauled. Thanks in advance!