Hi again Ian, from my research I have found that it is all rather confusing....there appears on Trove to be Ogden advertisements with and without the cowl...all from different dates though...
It also shows that I was wrong in my earlier assessment that your machine was a "Motamatic" and that it is an Ogden Power Mower, with the large oval decal (possibly carried over from the 1952 model which had the tank over the engine. wink
I still, however, believe it is a 1953 model.
Hoping this helps,
cheers2

Please do not PM me asking for support. Please post your questions in the appropriate forums, as the replies it may receive may help all members, not just the individual member.
Kindest Regards, Darryl grin