§ 314-a. Proof when witnesses are dead. When the witnesses to a conveyance, authorized to be recorded, are dead, its execution may be proved before any officer authorized to take within the state the acknowledgment and proof of conveyances, other than a commissioner of deeds, a notary public, or a justice of the peace. The proof of the execution must be made by satisfactory evidence of the death of all the witnesses thereto, and of the handwriting of such witnesses, or any one of them, and of the grantor, which evidence, with the name and residence of each witness examined, must be set forth by the officer taking the same, in his certificate of proof. A conveyance so proved, and certified, may be recorded in the proper office, if the original conveyance be at the same time deposited in the same office, there to remain for the inspection of all persons desiring to examine the same. If the conveyance affects real property in two or more counties, a certified copy of the conveyance, with the proof and certificates, may be recorded in each of such counties. Such recording and deposit are constructive notice of the execution of such conveyance to all purchasers of the same real property, or any part thereof, from the same vendor, his heirs or assigns, subsequent to such recording, but do not entitle the conveyance or the record thereof, or a transcript of the record, to be read in evidence.