The 6EA8 or 6GH8 (a pentode and a triode in one envelope) would be good front end tubes for a basic audio amp. The pentode makes a good input voltage amplifier stage, with the triode used as a phase inverter/driver. See the Dynaco Stereo 70 or MK3 schematics (all over the web) for typical implementations using the 7199 tube. Both types are dirt common, and cheap, unlike the 7199. I believe Heathkit used the 6EA8 in some of their amps, and the 6GH8 is used on many of the Dynaco upgrade boards.
The 2BU2 is the HV rectifier. A simple diode. Pretty useless these days. Same for the 17BE3 damper tube.
The 21HB5 was the horizontal output tube. A chunky little beam power tube without the usual plate cap found on TV sweep tubes. Other than the oddball heater voltage, a perfectly usable tube for audio or RF power amp applications. Could also be used as a series pass regulator for a power supply. 6HB5 is the same tube, with a more useful 6.3V filament.
The 3HA5 was likely the RF amp tube from the tuner. A low power, high frequency triode.
The 13Z10 was the audio tube. It contains a small beam power amplifier (audio output amp) and a somewhat less useful "gated beam FM discriminator" (Zenith loved these things), which was used as the FM sound detector stage.
10GK6 is a moderate power pentode, probably the video driver for the CRT or the vertical sweep amp.
10GN8 is a general purpose triode/pentode.
4BZ6 is a general purpose pentode, probably used as an IF amplifier.
8BA11 is a triode, as well as a weird dual-plate pentode. Probably used for the vertical oscillator and sync stages. Fairly useless.