Looking for pics of the main gun simulator used on US tanks prior to the Hoffman device. From the few pics it looks like a barrel mounted on top of the main gun. I'm guessing used early to mid sixties. I just can find many good pics or designs to try to scratch build one.

You just need to know where to Google Young Jedi.

Try this photo series taken at the Overloon Museum. Use the forward arrow to move through the images.

http://preservedtanks.com/Image.aspx?PhotoID=8392&UniqueID=1717&Page=1

It would be great to see the complete set up as an aftermarket item.