I recently repaired this Seth Thomas tambour mantel clock. It needed to have the pivots polished and 14 bushings installed.
This clock was a good example of original thin Seth Thomas mainsprings. The time mainspring is 3/4 inches wide and 0.0159 inches thick. It is in good condition and was retained in the clock. The strike mainspring was 0.0164 inches thick. I intended to keep it in the clock, but it broke after cleaning, so I installed a 3/4 inch wide, 0.0165 inches thick, and 96 inches long, Merritt’s Antiques part no. P-1956.
Here is a slideshow of the clock and its movement, and also the label on the bottom of the case:
Here is a movie of the clock ticking and striking:
Repair job 4854. The clock is 19 1/2 inches long.