H. Leach Machinery Co. was a machinery dealer. Earlier in their history they also manufactured machine tools, including surface grinders, tool grinders, and polishing lathes. So far as we can tell they were in business by 1939 and survived until 1982, although information is sparse enough that it is difficult to be certain.

Information Sources

• lathes.co.uk page on Leach surface grinders. They give the company address as 387 Charles Street, Providence.
• The worldcat site lists catalogs from this company: "Trade catalogs on plain and universal millers, milling machines, milling heads, vertical mill and jig borer, external and surface grinders, grinding machines and accessories, power presses, bench profiler, profiling machine and crank shaper". There is no guarantee that H. Leach Machinery Co. manufactured all these products as opposed to being a distributor or retailer.
• Seen on eBay: an undated but apparently 1950s desk blotter from "H. Leach Machinery Co. / 387 Charles Street / 295 Dyer Street / Providence RI / Liquidators / Appraisers / Machine tools, jewelers' machinery, grinders, power presses, milling machines / New and Used and Rebuilt / Electric motors, dynamos, generators, belting, pulleys, hangers, shafting, woodworking machinery".
• A history of the Frank Morrow Company includes this data point: "1939—A building with 10,000 square feet of space purchased on Baker Street from the H. Leach Machinery Co. ..."
• A personal web page on a Van Norman milling machine with a dealer plate from H. Leach Machinery Co. The page notes that that firm "appears to have been dissolved in March of 1982", based on a court-case summary found online.