Hi
I used to carry one of those in my caddy, it was used to crimp the pins on the CRT and other tubes. Some times the 6CD6, and other horiz output tubes ran so hot that the solder would "unsolder" and you could crimp the pins and get a few more hours out of them. Also there was a time when the 5U4 pins were not soldered well and I used this device to crimp them. At one time some of the tubes were not soldered very well and it came in handy. I am talking about 1960 to 1963 when I was in tv repair.
Joe