An interesting mower with some information already on this website, acquired this week & looks to be in original colours. I do like the height adjustment, reminds me of a 'Clapometer'!!
The mower was manufactured by Excelsior Motor Cycles in the early 1930's fitted with a Villiers Midget 98cc engine.
Whilst a 1934 advertisement states that the mower is fitted with Excelsiors world famous two stroke engine? At that time they were using Villiers Midget engines in their low cost motorcycles, therefore perhaps the ad was referring to villiers.
I know a member does have a similar model with a twin port engine, but perhaps a one off modification.
Another Monarch model had the fuel tank in a tool box similar to the 1930's Atco 'Tank in box'