The air vent is leaking a small drop of water from the valve on top . It has No.67 auto-vent Maid-O-Mist written on the side of it and was installed on the furnace when it was insalled in the late 1960's . I am wondering if this item is still available or is there another type that is available ? Living in a small outport community in Atlantic Canada doesn't make it easy getting parts .