That the governor be and he is hereby authorized to issue to the original purchaser or to any assignee who can show title in himself derived from an unbroken chain of assignments of a certificate of sale, issued by the commissioner of the state land office, a patent for the lands therein described: Provided, Said lands have been fully paid for to the state: And provided also, That the assignment, if made since the twenty-eighth day of April, 1846, shall be duly executed and acknowledged in the manner deeds are required to be by the laws of this state; but if such assignment that said assignee claims under was made prior to the twenty-eighth day of April, 1846, any informality therein may be waived, and such patent issued to such assignee upon a satisfactory showing that he is equitably entitled to the same.