This is an SCA Demodulator. I built this for fun when I was in college.
Look at the precision workmanship. This connects internally to a special spot in an ordinary FM radio (the discriminator, before de-emphasis) and it enables the radio to receive "store music" (remember Musak?). We used to hear other things like reading for the blind and even some messenging services. That's an NE565 phase-locked-loop IC and the three transistors are in sockets! Radio Shack had a small printed circuit board with etched copper pads and holes that aligned to 16-pin Dip IC packages. It was like a breakout box for ICs. That is what the IC is mounted on.