Is the -05 a later replacement/suitable for my mainframe or is the -05 a typo?
For your scope any revision of the CRT will work.
There were four revisions of 154-0644-0x, -00, -04, -05 and -09. Only -00 (< B040600) and -05 (repl for -00 and used from B040600)
were used in 7704A. The other two were used by 7854 and 790x series opt 78 i.e P11 phosphor. For some reason 7704A opt 78 used another CRT.
If the CRT was replaced on 7704A below B221300 a Part Replacement kit (050-1732-01) was required. It contained the -05 CRT and two resistors
(one for 7704A and one for 7904/R7903) used to reduce the heater voltage to extend CRT life.
Kit instructions here:
/H?kan
zenith5106