Here is Gil Carlson's circa-1951 patent for the Bell & Gossett Flo-Control Valve. Thanks to Steve Pajek for finding and sharing this document.
This document contains the manufacturer's instructions for the HB Smith Series M450L Mills Water-Tube Boiler for automatic firing with oil or gas (Steam, Vapor, or Water ...
This document contains the jacket assembly instructions for the HB Smith Series 45 Mills Boiler (circa 1979).
This document contains the combustion chamber assembly instructions for the HB Smith Series 45 Mills Water-Tube Boiler for automatic firing with oil or gas (Steam, Vapor,...