During the late 1920s and early 1930s the Colchester Master (and possibly other models) was supplied by the then well-known machinery dealers Selson disguised as the "Osborne". As usual with this sort of "trickery" the seller simple arranged for a batch of easily-changed castings (in this case the changewheel guard) to be made up with some invented name.
Selson were British (with overseas branches, especially in the colonies) and established in 1871. From early in the 20th century they were mainly importers, agents and distributors who handled a very wide variety of machine tools. Although they never undertook manufacturing themselves, their enormous buying power enabled them to commission batches of machines, complete with a Selson badge or even the name (or an invented name) cast into the main structure or some easily-changed part, for sale exclusively by themselves.
Although their large, well-produced and hard-bound catalogues contained pages where the maker was clearly displayed, many had machines where any reference was missing, even to having nameplates and logos obliterated (often crudely) from the printing block
During the 1950s the Company was acquired by the 600 Group, itself a merger of various interests of the long-established George Cohen, Sons and Company.
Other important machine-tool companies acquired included:
Colchester Lathes 1954
Gamet Products Ltd. maker of high-precision bearings 1956
Midgley and Sutcliffe Ltd. 1954
F. Burnerd & Co. chuck maker 1953
Richmond Machine Tool Co. Ltd.1963
W. E. Sykes gear machinery 1966
Typical examples of Selson-badged machine tools include Volman and Robot and Colchester lathes disguised as Osborne.

A typical geared-head Selson manufactured by the Simplex Company of in America. This model was sold from the early until late 1930s onwards branded, in the United Kingdom, as the "Regent"