Video shows the man knocking over and shattering a $1,500 clock in front of Stair's Incurable Collector on September 27.
The clock was not insured.
Workers were preparing to mount it to the building.
According to the store, the clock was bolted to a pole.
Police are offering a cash reward for information leading to an arrest.
Anyone with information can contact Suffolk County Crime Stoppers to submit an anonymous tip by calling 1-800-220-TIPS.
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