Provided, That where the owner or owners of land sold as aforesaid, shall, at the time of such sale, be an orphan or orphans, or insane, and residing within the United States, two years after such disability is removed, shall be allowed such person or persons, their heirs or legal representatives, to bring their suit or action for recovery of the lands so sold, but where the recovery is affected in such cases, the value of the improvements made on the land so sold, after the sale thereof, shall be ascertained by the jury trying the action for recovery, and paid by the person or persons recovering the same, before he, she or they shall obtain possession of the lands so recovered.