I have it down as new as a Traction Engine. This is how it appeared at Elsworth Rally in 1955 and was then named 'Nancy' before it went derelict(ish) and was ultimately rescued by Stan Burgess.
I have some of Stan's photos and there are quite a lot of close ups of 'Monarch'.
Really apart from the canopy looking a lot less like a garden shed, motion covers and the stars on the cylinder not a lot has changed.