Yours will be an original from Donald Cranko workshop.
Stamped Cranko inside a Diamond . Earlier engines have Cranko NZ. ( no diamond )
When Cranko closed down some of his parts ended up in Auckland at the “ Auckland Model Engineers “ . They assembled horizontal and vertical used a different darker green and paper label.
The one you showed in the steam bible has been fiddled with .
Did you look at the link i did with the -photos of my two in original used condition
Cheers
Dennis
These two engines by Graham Heavey, a vertical and a horizontal, seem to have many of the same parts, such as the frame. That was another reason I had been concerned that it was a reproduction. Are these the engines you're talking about?
https://www.toyenginecollector.com/toys/search/?mfg__name__icontains=Steam+Craft