Here on page 512 of the Sears 1969 Christmas Wish Book is a model of the Saturn V rocket that had, on July 11 of the same year, safely delivered American astronauts to the surface of the moon and back home again. There is also a Visible V-8 Engine model. Someone gave me one of those for Christmas, probably into the 1969 timeframe, but I did such a lousy job of assembling it that the pistons and valves wouldn't budge by the time I was finished with it. Little did I know at the time that it would be an accurate replica of 350 cu.in. engine that I had in my 1969 (ironically) Camaro about seven years later - yup, it blew a ring and locked up on me :-(
Use the U.S. Bureau of Labor Statistics' inflation calculator to see what items cost in today's dollars. That $9.99 Erector Set would cost $59.53 in 2010 money.
Here is a YouTube video of a Visible V-8 Engine running at over 5,000 rpm!
Posted November 20, 2010