This 'scope apparently was developed in the '60's, though I think my one was made later, so I'll stick with the old tech rather than start messing about with it!
Years ago I had a Cossor which was altogether not much bigger than the tube in this one, lovely little thing, all valve, no graticule but a metal cover to protect the screen when not in use. No calibration. I wrote to Cossor to ask if they had a manual for it, but it was so old they only had one for the MKII (which had solid state rectifiers!). I made the mistake of lending it to my so-called friend, who promptly dismantled it. *******.
The only other 'scope I've owned is one that I made from the Babini book "How to build your own solid state oscilloscope". Again, uncalibrated, but it was pretty good, all considered.
So this one is /way/ advanced!