A license plate issued pursuant to this article may be transferred to another vehicle of the same weight class owned by the same person upon application being made therefor, in a manner and upon forms which must be prescribed by the Department, and upon approval of the application by the Department. It is unlawful for any person to whom a plate has been issued pursuant to this article knowingly to permit it to be displayed on any vehicle except that one authorized by the Department. If a holder of the plate ceases to be a volunteer fireman he must immediately return the plate to the Department.