A friend was arrested for having a "billy club" in his car. He was on probation at the time. The item was actually a short ax handle which used to hold up the hood of his car, because the original mechanism was broken. He used to hold a job that required use of a billy club, and thus had a license. He was told that those types of licenses are valid for life.
Criminal Defense Attorney
Two issues. The handle he used may not even be baton in the first place. That is a legal determination. Second as it relates to your question, the baton permit is valid so long as the person has a valid guard card or is a police officer.
The above information does not establish an attorney client relationship nor is it meant to provide legal advice.