I was doing some long overdue testing on a tube distortion unit. There isn’t a lot of space in the unit and they had these Cinch tube shields on the tubes that look a lot like this: They fit snuggly on the socket, they have some kind of array of metal prongs that grab the tube very tightly inside. These are actually a punched sheet of spring metal that is stuffed in there. To put the shields on one of the tubes in the unit, you would need to place the shield on the tube, put the tube in place in the socket, plug the tube into the socket by pushing on the tube through the top of the shield before seating the tube shield. I found this impossible. Am I missing something?