I bought a new [to me] HP 3312A. I got it for a good price since it was sold "For Parts" because of missing knob caps and (blue) center push buttons. I've since replaced the push buttons with a small length of wire insulation and a bit of Q-Tip stem as filler (the white part).
This beast is all analog; no MCU inside. I'm just amazed at how well-engineered it is. From the front-panel aesthetics and over-loaded yet intuitive controls, to the Lego-like case that's built like a tank, to its gold traced PCBs and laced wire everywhere. It's vintage '82 and after 40 years, it still works (and smells) great.
I also picked-up two HP 59301As for a very good price. Back in the day, they were used to make some all-analog HP test equipment GPIB-aware; ie. "programming". Basically, you push a 16-byte string to it and the bits are placed onto two 50-pin Centronics-type (telecom) connectors as TTL; like the way we use GPIO pins on todays MCUs to interface to the analog world.
I bought them for the case and 5V power supply. I'll just substitute my own PCB and new front panel, and voilà, fits right in with my other test equipment!