I'm very curious about this. My father put together a Heathkit (analog, of course) oscilloscope kit when I was a kid. It took me years to realize the amount of dedication involved in not just assembling the thing (which I helped do) but also importing it to Portugal from the US.
My dad built one of these: https://www.youtube.com/watch?v=iad37q9kNPk and we spent a lot of time looking at our house power and trying to figure out where recurring patterns came from. Back in the early 70s, refrigerators and air conditioners (things with high-load motors running intermittently) were often the culprit.
He built a bunch of Heathkit products. We had an intercom system that worked over the power wiring. It quit working before I was clever enough to use it to play jokes on my little sister.
(I'm 95% certain it was this one: https://www.youtube.com/watch?v=hoAmzsz_bJY - the knobs on ours were slightly different, though.)
I don't think they'll be doing oscilloscopes again, but I remember they had a kit catalogue I loved to pore over.