See this list:

Besson Serial Numbers
http://www.dwerden.com/blog3/postima...ialNumbers.png

(Depending on your browser, you may need to click the screen once you open the link to see it full size)

(And from Doug Ruby)
Here is another list of Besson Serial numbers from the Horniman Museum.
http://www.horniman.ac.uk/media/_fil...dlists_web.pdf