Well I went down another rabbit hole this evening looking at my family photos from before the 50’s and I came across this photo…
It almost looks like there is a tyre on the big wheel. The peaked caps make me think interwar, but it is a period I know very little about.
The other problem is I don’t know if the photo shows the front or the back!
All in all I am stumped!
Bogenwald 
Off the top of me head without the chance to look anything up I’d say it’s something like a Vickers Light Dragon MkII gun tractor or something similar from the 1930s. Early War Miniatures make something that looks similar in 20mm scale! I’d say you were spot on with the 1930s though! Hope this might help!
LikeLiked by 4 people
Cheers John I reckon you are right, I found a mk3 of the Dragon on the IWM Web page so had a name.looks like the mk2 front end. The cylindrical thing in the side was a give away on any photos. Funnily enough my search was for interwar tracked artillery tractors.
LikeLiked by 3 people
Reblogged this on ausevor.
LikeLike
I agree with John. It looks like the light dragon to me as well:
https://en.wikipedia.org/wiki/Vickers_Light_Dragon
LikeLiked by 2 people
Make my vote the same!
LikeLiked by 1 person