Trenchbuff, thanks for adding the painted Reserve Mallet tin plate, I'd never seen anything like that before. I have two or three photos of AEF ambulances bearing additional insignia that are unknown to me. The resolution was so bad that I chose not to post them, not sure, but maybe I'll add them anyway as there may be a chance that someone will recognize what they are.
I have a file folder devoted to medical treatment in the AEF, which I forgot to look through. Your addition of the Reserve Mallet insignia reminded me that I still need to check that folder for vehicle insignia. Also the toy truck bearing the insignia of the 79th Division is great - what a neat find.
Thanks also to the trio of posters for looking at and commenting on this post. I have a few additional photos that were just emailed to me which I will be adding soon