The June 2015 issue of Heritage Commercials has an interesting article about EMA ( Electric-Mobile-Aerodrome) cranes and their later fitting to the Thornycroft Amazon Coles crane and other chassis. This article is continued into the July issue with much more information and lots of photos.
Here is the cover and the main photo. I hope I am not going against a copyright issue here as it is promoting their magazine in some way.
Regards Rick.