To what end? If you want to make your own scope, might as well find an NOS (= they don't make them anymore, but there's plenty on the shelves) 5AP1 or something like that. Same goes for Tek replacement parts, for example.
Or for TV, any junker will do: the yoke coils and flyback are even included for you.
If you have a very special CRT that needs repair, you may be SOL, or nearly so: my brother is involved in the Early Television Museum, and vacationed in France last year, visiting one of the last (if not the last, I forget) shops capable of CRT repair.
Tim