audio control on this project has been my biggest enemy, i tried for awhile to have it controlled on the PI (which would have been a much better solution) but ended up with just building a circuit for it. Even this one isn't very clean, currently it has a few issues with the volume, notably the fact that i only have 10k pots laying around so the range on the volume is entirely controlled by the first quarter turn. and the two boards are slightly redundant, i had much better results on my breadboard by running two modules each with a different channel. the volume is controlled by a pot which essentially just shorts the signal to ground in varying degrees and prevents it from getting to the modules (the pots going to be mounted to the inside of the radio and not the board, the header is for wires to come in). the connectors make the hookup nice and easy. All and all i'm decently happy with this board, its hit the point of "good enough" for this project, especially considering the quality of the audio from the archive.
i also forgot to mention that the attiny sitting in the corner is its own circuit, its for communication to the PI. it just activates a pin when it detects a significant change in the pot its connected to. the entire attiny circuit runs on 3.3v directly from the PI.
all that's left to do is to put the circuit in the radio box and see how it all works together, hopefully there's more project logs comming!