Hi Shedpest and congrats on a great score there mate, what a little ripper!
As you can see on the manufacturers ID plate, the mower was manufactured by L.J. Phillips, in Mentone, Vic. This company commenced trading in the early 1950's and produced many different types of petrol engined scythes and rotaries for different applications. Back in their day, they were considered by some as the Rolls-Royce of rotaries....until sales were overtaken by Victa with the Special 18.....
In the early years, the Villiers engine was preferred and your Midget (Model 3G) was very popular and strong engine.
Have a look at the brochure;
HERE 
