§ 243. Extension of time. The time within which any act is required to be done under the foregoing sections of this article may be extended by the supreme court for good cause shown, for one year, and but one extension will be granted. Any company that has heretofore constructed or is now operating an elevated railroad shall be deemed to have been duly incorporated notwithstanding any failure on the part of commissioners to insert in its articles of association provisions complying with statutory requirements relative to such articles.