1921:
H.G.Hawker Engineering Co Ltd
Hawker Motor Cycles - Hawker Two-Stroke, Two-Speed Lightweight
Rec. Num. 1 of 2
Source: The Motor Cycle June 23rd 1921
1922:
H.G.Hawker Engineering Co Ltd
The 1922 Hawker Motor Cycle Range - Hawker Models A- D
Rec. Num. 2 of 2
Source: The Motor Cycle April 6th 1922