The mystery was resolved when I removed the paper cap C9 and discovered it
was a replacement, done back around the late '40s or so, with a cap not
unlike the ones Zenith used. The job was very well done, except that the
sleeved lead he clipped off at the old cap body was left behind. That also
explains why the sleeved 'stub' is exactly as long as the capacitor lead
above.
While I was restuffing the caps, I found that the 'across the line' cap C6
had failed and the lead spiral had been dislodged from the capacitor roll
and some arcing had taken place. It undoubtedly would have gone 'pop' when
it happened. The cap is certainly different from the 'normal' paper caps
used and is marked as 0.05uF 400VDC and has a different stock number than
called in the parts list.

Neil S.

1. there is a sleeved wire coming from the grid of the 3Q5 output tube
and laying across the socket of the 117Z6 rectifier, but not connected
at
the far end. According to the schematic and common sense, this wire
serves no purpose, but is clearly factory original. In photo see it
coming from the tag just behind the 2.2meg resistor and across the
socket
and ending over the grey wire. Since the grid impedance is almost a
megohm, one might think it would pick up hum.

Neil S.
Are C9 and R6 in the circuit? Ken