Antique AIRCO Regulator Valve Pattent dated 1895 1901-03 brass steampunk patina

Description

From dads friend J.Williams and the firehall so I am unsure what it was used for. is untested, VERY LARGE adjuster turns, nice green patina, pat. dated march 5 1901-oct 22 1895-aug 25 1903. SOLD AS IS NO RETURN, USPS Shipping to lower 48 United States.