In USA the chain drive solution for high tension magnetos seems to be rare but not here in Sweden - though most were homemade in the 30's or later when the T engines were used as threshing engines. Never saw a KW chain drive, but Bosch did market their version both in USA and Sweden.
Here is a Dixie version: http://www.mtfca.com/discus/messages/331880/375902.html?1374535682
And here is a page from Bosch News in 1923 showing their chain drive:
I had a bosch chain drive on my table at Chickasha, never saw anybody look at it.charley
Charley I specifically asked folks to look for me any type of accessory magneto drive because I'd really like to get it. What are you asking for it?
Seth! send me your e-mail so I can send pixs.it was $750.00 with the right mag, obo. charley