I have a USA Coleman lamp stamped CQ on the handle which is 4 1/2" tall. (1917 onwards). The handle was shortened to 3 3/4" on CQ models from approximately 1919. The generator is stamped only with the US patent May 13 1919 on the generator. The Coleman Guide book places this approximately 1919 onwards but before Fall 1924 when the British patent was added to the genny. Am I right to hope and presume since my lamp has one indicator of being approx 1919+ but retains the pre-1919 handle height that the handle may have been getting used up and the manufacturing date would be closer to 1919-20 rather than the broader range of 1919 to mid 1924? The fount base is unstamped. Iain
Lain I find the transition date to be in 1922... But I don't always agree with the guide book. In my opinion if you have a short fount tall handle CQ with the single patent date stamp on the air tube, you're looking at the 1919-early22 date range.
