§ 925. Certificate of searching records and copies. The clerk of any of the counties comprising the city of New York, upon payment of the fee prescribed therefor, shall diligently search the files, papers, records and dockets in his office, when so requested, and make one or more transcripts therefrom, and certify to the correctness thereof, or certify that a document or paper, of which the custody legally belongs to him, cannot be found.