Interesting, I hadn't seen that yet! (not strange, too: my wife always jokes to me I'm looking with my ears, I never seem to find things I lost!)
One other thing crossed my mind as to it's use... my dad has electrically heated gloves for his motorcycle in winter. Were there heated flight suits or gloves in WWI?
Good to know it is similar to the one in the Rumpler kit.
Thanks, Jeroen