Here is another “Plymouth” tambour mantel clock by Seth Thomas (see this post for two others). This one does not have a date code, I estimate that it is from the early 1930s. It has a no. 89I movement that strikes the hours and half-hours on a coil gong. The movement has a code of R-6 on the back.
The case is 19 3/4 inches wide and 9 1/4 inches tall. The dial has a 4.5 inch time track, and is aluminum with embossed and painted numerals.
The movement has the original mainsprings that still open up very far and provide plenty of power. They are 3/4 inch wide loop end springs. The thicknesses are:
Time mainspring: 0.017 inch
Strike mainspring: 0.0167 inch
Job 5146. I had last repaired this clock over 10 years ago, and it just needed to be disassembled and cleaned to make it run well again.