Thank you so much everyone for your welcome and for your fab answers!
I think the kids might need to write this one down then, but we're going with "reduced pattern striped coastal carpet python" - love it!
I thought it was a bit odd that I couldn't find any snakes online looking like this, so quite nice to hear about how unusual he is. Do you think he could perhaps have been bred for this colouration and may be an escaped pet?
I spotted him roaming wild, but did allow me to get quite close to take pictures

I was itching to pick him up but as it was our first time in Oz, land of the deadly snakes, I decided for the benefit of the kids memories that I shouldn't!
I've never owned a snake but I would love to one day. Every now and then when we pass a 'reptile house' I go in and ask to hold their snakes under the guise of looking to buy one. A bit naughty! but I love to handle them and really would like to have one at some point, when I have the space and time to dedicate to him
Thanks again everyone for your replies. Perhaps we will cross paths again in the future