What a find Bruce!!!!
Many of our Kiwi/Aussie Friends that worship David Auld will be very jealous.
I found one example that sold in 2011 on my Worthpoint Subscription Database. It was sold out of Mexico for $299.00 on eBay (a steal IMHO). They claimed in the write-up that there were only 30 made.
Here is a thread on the Mamod Forum from February 2017:
https://www.tapatalk.com/groups/modelsteam/gold-coast-auction-and-david-auld-steam-launch-t93937.htmlAt that auction in 2017, a David Auld Steam Launch sold for $1300 AU which is $1033.06 USD today.
Scalex (Andrew) also has one of these and he has steamed his. You might reach out to him. I posted a link to your video on your YouTube page in the link above noting that now there is a 7th known one.