I was able to get a new air filter assembly from Meetens for a few years ago.
Controls should be throttle on righthand side, on the left lever for swinging handlebars left and right, underneath is clutch lever.
On my Monro Minor the locking mechanism for handle bar swing was seized.
I have no information on dates of production or serial numbers. A magazine article I have from Amateur Gardening dated 15th Sept 1962 suggests it was a new model then.
Later versions produced by Mechanised Gardening of Great Gransden, were called the Crunchtiller and had a different engine.