Hi Ringo.
This may be thinking outside of the box, but there is a Colt 8 for sale on Gumtree at: -
http://www.gumtree.com.au/s-ad/kemp...on-ride-on-mower-ready-to-mow/1093741575
If it is similar to yours, maybe you could message the owner and ask for their model and engine details to give you an idea???
Have you tried emailing Rover Australia direct?
Just a thought.
Daryl

Environmentally friendly recycling at it's best