174. The provisions of sections 168 to 173 shall, so far as they can be made applicable, apply in the case of an officer who, notwithstanding anything contained in the Lunacy Act, 1912, is ascertained in the prescribed manner to be insane, or, who, being on active service, is officially reported missing as if he had died on the day on which his insanity is so ascertained or, as the case may be, on the day on which he is officially reported missing: Provided that in the case of an officer so reported missing no action shall be taken under sub-sections (2) to (5) of section 168 until such time as he is officially presumed to be dead.