Any corporation or association organized in this state under previously existing statutes may, by a majority vote of its stockholders or members, be brought under the provisions of this article by limiting its membership and adopting the other restrictions as provided herein. It shall make out in duplicate a statement signed and sworn to by its directors to the effect that the corporation or association has, by a majority vote of the stockholders or members, decided to accept the benefits and be bound by the provisions of this article and has authorized all changes accordingly. Articles of incorporation shall be filed as required in section six of this article, except that they shall be signed by the members of the then board of directors. The filing fee shall be the same as for filing an amendment to articles of incorporation.

Where any association may be incorporated under this article, all contracts made prior to the date of incorporation, by or on behalf of such association by the promoters thereof in anticipation of its becoming incorporated under the laws of this state, whether or not such contracts be made by or in the name of some corporation organized elsewhere, and when they would have been valid if entered into subsequent to such date, shall be held valid as if made after such date.