[Someone]

Talk to a lawyer. Trademarks do not have to be registered, at least not in the USA.

https://en.wikipedia.org/wiki/United_States_trademark_law:

”Common law trademark rights are acquired automatically when a business uses a name or logo in commerce, and are enforceable in state courts. Marks registered with the U.S. Patent and Trademark Office are given a higher degree of protection in federal courts than unregistered marks“

[bizgrayson]

Definitely, it has not been used it a very long time - but I'll check with someone.