Act No. 15 of the Public Acts of 1923, being section 15611 to 15623, inclusive, of the Compiled Laws of 1929, is hereby repealed, except that all appointments made thereunder and all letters of administration issued to the state public administrator or to any county public administrator by virtue of said act, shall remain valid and such state public administrator or such county public administrator heretofore appointed as fiduciary of any such estate under the provisions of that act or pursuant to the general probate laws of this state, shall be subject to the provisions of this act. Nothing in this act shall be construed to repeal the provisions of Act. No. 288 of the Public Acts of 1939, and amendments thereto, and any parts of this act inconsistent therewith shall be deemed to modify that act only to that extent.