The Sigma was produced form 1913-1928 and was quite successful. They used Ballot engine.
Westair Active member Fellow Frogger Joined Jan 5, 2005 Messages 552 Location Perth May 16, 2005 #1 The Sigma was produced form 1913-1928 and was quite successful. They used Ballot engine. Attachments Sigma 1914.jpg 18 KB · Views: 321
