For what it's worth, they're described as "ceramic" in the Rider's parts list, although I guess that could mean garbage paper dielectric inside a ceramic tube.
All (14!) of them occur in the audio & video IF sections, where they are used for bypass, AGC filtering, and decoupling, according to Sams. Examples: C6/C8, C10/C11, and C13/C14 in this schematic snip:
http://antiqueradio.org/art/Emerson6...io-VideoIF.jpg
I'm usually loath to replace a dozen of anything in the video IF, because . . . alignment.
Phil Nelson