Any firearm which cannot be legally owned, possessed, used or carried pursuant to this Act but which was legally possessed, owned, used or carried prior to the effective date of this Act may not be registered hereafter. However, the owner or possessor may retain said weapons until the time specified in § 60123, at which time he must dispose of the firearm. If he cannot do so without loss to himself, the Department is authorized to purchase the firearm from the legal owner based upon the fair market value at the time of last eligibility to possess or own as stated in § 60123, and keep or dispose of the firearm as the Chief of Police determines.

SOURCE: GC § 8909.1.