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The fact that you are getting 92.3 means that your audio IF (in fact the entire audio section) is working correctly. Your problem is almost certainly the LO frequency.
You are receiving 92.3 FM on channel one because there are two products that are created in the mixer. Usually, you would get a product of LO minus the audio IF frequency (87.0 - 21.25 = 65.75). Here you are getting LO plus the audio IF frequency (71.05 + 21.25 -= 92.3).
I use a tube shield over the LO tube, connected to the frequency counter input. Pull the shield up so it doesnt touch the chassis. Be sure to connect the ground lead of the counter to the chassis near the tube shield. This should produce an accurate result.
I would use a VCR with channel 3 output as your signal source. Then, adjust the LO slug for channel 3 for 65.75 plus the audio IF frequency (LO should be 87.0 mHz). Then, listen for audio. Move the LO slightly above and below the proper frequency, since the IF may have been peaked for something slightly different from the specs.
If you have no sound after this, check the plate, screen grid, and cathode voltages on the audio IF tubes. Obviously you should also check the tubes themselves. After all this if there is still no audio, then do the alignment.
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