Seth Thomas Clocks

[SS427]

If I understood what I read on line correctly the patent was issued between 1949-1950 but only means this type of movement got it's patent from that date until the next patent change and was good for many years. It is also pre 1982 as they moved to Norcross, GA that year. All I can find using other ST office clocks for a comparison, the Hurst logo and some other details, I come up with mid to late 60's but cannot narrow it down to a specific year. There are enough numbers on the back that one of them should be some sort of date stamp but if it is I cannot find it on the net.