This DVD was picked up in a flea market at The Rocks and has no indication of when it was originally produced. Apologies if any copyright has been infringed - but it deserves a wider audience!
Update/Sept 2018:
Paul Robinson (in a comment below) has pointed out that it was produced as a 75th-anniversary project by the Sydney Division of the Institution of Engineers Australia. [Now named Engineers Australia - see www.engineersaustralia.org.au/About-Us/Divisions/Sydney ]
Update: April 2019:
YouTube appears to have started adding Ads to the start of the video :(
I can't see any way of preventing this, so have linked to an 'AdSense' account. *If* any revenue appears, it will be donated to charity.