Welcome to Massey Collectors Buck,
I am looking forward to hearing more Massey history and seeing your projects from Australia, so please keep posting away, this is the place for all things Wallis and Massey.
I am pretty sure John has nailed your tractor down, from the two photographs it looks like a green unstyled OPA, we look forward to more photographs especially the manifold and carburetor side of the engine.
Expect Tom Seaberg will soon be on here and keen to add your tractor to his growing list, what is the serial number?
Good luck with your projects and let's see some "Sunshine" Massey's on here.