MatEck

Jim: just a note - my grandfather was Arnold Jonker - the "window dresser". He was a commercial artist in the Detroit, MI area. He spent most of his time as a commercial artist - I think for a company called Cadillac (not car nameplate but a graphic arts company). Somewhere I have a business card of his. He was not an engineer. I do remember being told that he did some drawings of tanks and other equipment during the war - but I think these drawings were for sales brochures. I'm not sure from your post what you are looking for, but if you need me to ask around with my relatives, i would be happy to do that. Matt Eckman. (I can be reached at the contact form at https://myvideousa.com/contact/