If a 2024 1120-S is required, follow the law.  If it is not required, then don't file one.  Seems to me that it is still in business, collecting payments on the sale.  What happens if the buyer defaults?  Who sues him?  The S Corp?  What if its franchise has been revoked for failure to file returns?  And we still don't  know if this is an LLC or a corporation.