I have discovered that there was a Cycle manufacturer in Southampton that also made Motorcycles, from about 1907-1925. William Charles Ackland (1871-1942) founded the W.C.Ackland Motor and Cycle Company (1895-1936) and ran it with his son, William George Ackland (1903-1994). There is one example of an Ackland Motorcycle in Southampton Museum. It dates from 1922, with a 680cc V twin JAP engine and 3 speed Sturmey Archer box.
That appears to be the limit of knowledge on the subject.
I am interested in any information about Ackland, photos, brochures, press articles, another example, just about anything. If you know something please get in touch.