One last thing, testing CW uses none of the IF and modulator so if it works you can't know if the IF is fine.
MUST test using SSB. Ideal bias for Q20 will have the collector at about 6V (+-1V). To high or low
and it functions poorly. In mine the 3904s had it at 3.5V, that is too low. This is typical of normal
variations across different device lots devices.