Arthur Thomas Howson (1866-1928) trained as an accordion maker in his father's Nottingham workshop but at some point moved to London and started making his own instruments. 

In 1906 the workshop started producing one string fiddles based on the Horn Resonator concept and went on to produce at least one Ukulele variant of the Phono-Fiddle. These all bore a small black plaque or decal saying A.T. Howson, London, and sometimes Maker was added too. In addition to this it was sometimes stamped on the horn. according to the British Museum they were in production until the late 1930s

The Howson workshop also produced inexpensive banjoleles for J.T.C. - L. and possibly others. They may also have put them out under their own name? What I have seen is the name stamped on the headstock in a similar manner to the G.H.&S. British Made stamp.