Probably so that it could concentrate its efforts more lucratively elsewhere as the post-WW2 economy in Californian machine shops started to revive, on August 4, 1949 Small Machines Incorporated was sold/spun off as going business to MasterSon Engineering Co. of 1416 Westwood Boulevard, Los Angeles. In 1953/54 (just three years before their demise) they introduced a line of three new lathes that used the model description "Master". The cheapest in the range was the  Master "Model S" - for "Standard" - with simple bronze spindle bearings; a higher-speed version was also offered, the Master "Model BS" -  for "Ball Bearing Standard" - with a ball-race headstock whilst the top-of the range version was the Master "Model BWW" - for "Ball Bearing Large Spindle". This latter machine had a large-bore spindle with the nose formed to accept standard  8 mm WW type collets. Although the models "S" and "BS" were fitted with a set of fixed-ratio fibre changewheels (though the last in the train was brass) to provide a power feed to the carriage the "BWW" was offered with changewheels for screwcutting - though this is a very rare machine indeed. Also listed amongst the accessories was a thread-dial indicator, a built-on countershaft unit to give a selection of spindle speeds and various "factory-installed accessories" - a remarkable achievement in a lathe only 10 inches long, though unfortunately non of these extras ever appear to have been shown in the sparsely-illustrated company's advertising literature.
Unfortunately the Master range did not have the backgear arrangement of the Duo lathe, nor the variable-speed motor, but it did retain the graduated cross-feed screw micrometer collar and greatly-improved design of tailstock. Instead of the cross-slide gib strip being a non-adjustable "corrugated" strip of spring steel, the Master range was equipped with two pusher screws fitted through the right-hand face of the slide. By this time the accessory case had become metal (neatly made and carrying a small company badge), and also available (though this is not absolutely certain) was a neat carry-case, with reinforced corners, designed to house the lathe.
With so few years in production only very few this model can have been made and, if any reader has an example in their ownership, the writer would be interested to hear from you.
As of June, 2011 the lathe below is for sale.
Phone: 01298-871633 or, from overseas: **44-1298-871633 or email: tony@lathes.co.uk