That's a very good find, 2" IO are as rare as hens teeth! well done.
I do not know of any cameras that use 2" tubes I expect they were all special purpose. X-ray or astronomical cameras. There were some Image Isocon tubes made for these low light jobs and there were 55mm. ones made, but they to are very rare.
The Image Isocons had more electrodes and more pins on the base connector. I have a 4.5 inch image isocon in the collection and the picture shows the tube with a 4.5" IO and a 18mm. plumbicon for scale. Mine has a curved front faceplate and was used in this camera
http://www.tvcameramuseum.org/marcon...6/isoconp1.htm
If you are able to take some good pictures of your tubes I would be interested in copies of the for my web site when I eventually get round to doing the "tubes" section. Tubes are hard to take with a flash, best to do them outside on a good day to avoid flash bounce back.
About the plastic "inversion cylinder" If your tube arrived having been inverted you were intiltled to send it back as unusable, such was the concern for a blemish free target. a serious business considering the cost of the tubes! I the early days the BBC would not buy tubes but had them on "rental" and returned them after a certain number of hours of use.
regards Brian
www.tvcameramuseum.org