Antique Mantle clock with alabaster or marble columns

My Grandfather bought this clock at an Auction in May of 1953 in South Dakota. At the site of the Pactola Dam. The town of Pactola was flooded to create Pactola Lake. The auction was held before the town was flooded. This clock came out of an abandoned store. My father gave it to me recently and I am trying to figure out where it was made, how old it is etc. I brought it to a clock repair man and he was able to get it running. The clock was missing one of the hands, and the keys. It is a 24 hour clock that chimes on the hour and 1/2 hour. It seems to keep time very well. The repair man cleaned the metal face and pendulum. He had to replace the main spring in the mechanism. There are holes on the top of the clock where decorative pieces once sat. The only markings I can find are on the handle to the glass door. They look like A:ST Thank you

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