I could help if non-professionals could be of any use.
It's all turned out good.
yep, thanks Chris... I guess I should have updated this sooner. When they found him around 5:45am today I just went straight back to bed.
He was apparently quite cold and scared but otherwise unharmed and perfectly healthy after being missing for a total of ~10 hours. Still waiting to hear exactly where they found him.
Wow, that's a long time for a 3-year-old to be alone in the woods on a cold and (around here) rainy night. And a long time for his parents to worry. So glad it turned out well.
SAR just found a little guy (2) in Kimberley as well, so an all around good day.