Oscilloscope CRTs haven't had curved faces since about 1930. Later ones are all flat.
The o'scope lens would be only slightly better than a dime store magnifying glass.
They're "optimized" (if I can use that term very loosely) for 1:1 ratio, so if focused
at infinity the image circle will only be about 2" (half the CRT display width).
I wouldn't waste much time with it.