Yes. Counterfeit SilverTowne 1 oz silver bars exist and have circulated on eBay and other online marketplaces.
Most are silver-plated brass made in Chinese facilities, replicating the design accurately, including the “.999 fine silver” and “1 troy ounce” markings, even though they’re actually silver-plated brass, sold online for well under $1 each in bulk.
Documented differences include slightly lower weight, narrower width, and thinner text on the front, plus incorrect logo orientation and detail on the reverse side. Some counterfeits are convincing enough that dimensional or weight checks, or a Precious Metals Verifier, are needed to catch them.
Buying only from established, reputable dealers is the best protection.