(The following photos and description provided courtesy of Bob Hess.)
This laser from Hughes Aircraft Company was built in 1962, less than 2 years after the first demonstration of a working laser by Theodore Maiman on May 16, 1960.
It's based on the original design. Mine has dielectric coatings directly on the rod ends, and gives up to 1.5 J, which I've measured. I pulse it about once a month just to keep the capacitors and relay happy. It runs with the Model 250 power supply, and I have the original cables for it too.
I spoke with Doug Buddenhagen who headed the group of about ten who built it. After Maiman made the first laser, Hughes immediately started the program to make a laser radar and Doug was in that group. After that, they started the group to commercialize a basic laser and this is the first model. The sticker on mine suggests it was built in the third quarter of 1962. The only older commercial laser would be one made by Trion, but I'm willing to bet that the few of those that were made (before it was sold to Lear/Seigler about the same time my laser was made) haven't survived, and certainly not in a working condition.