Greg,
I'd add separating the sidetone and audio with common connection to the volume control.?
I did that by lifting one and of C and pin 2 of the LM386. Made a connection by lifting one?
end of the C and lifting pin 2 and connecting the C to pin 2 via a 1 meg resistor using a SIP.?
Also, I use a 5-el HPF with attenuation from
about -70dB to -40dB across the AM band.
If interested, I'll send the details via PM...
Chuck Carpenter