LOL, found dad's old paperwork for the ride on:
He bought it second hand in 1994, and it was old then:
'twas an 8HP apparently (I thought it was less) but that engine blew up.
He bought the new 10.5HP engine in 1998, at the time it was the biggest one we could get that fit:
I'm not sure how old the mower itself is exactly but I did find the instruction book:
If you look down the bottom, you can note the SIX DIGIT phone number.
Now I remember going from 7 to 8 digits some time in primary school, but 6?
Some quick research, and this very informative page tells me that "Brisbane went to 7 digits in 1975". Therefore, we can conclude that the beast is older than 1975. Thats 35+ years!
And note: it is a mini tractor, not a ride on . EEESSSSSSS AAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRRRRRRRR!!!!!!!!!!!!!!!!!!!!!!
Look, you can (could) even get tractor attachments for it:
Definitely needs turbo love