Billy Preston with a Univox Compac-Piano
Univox (brief company history here) was a US company that marketed a huge range of musical products in the late 60s and into the early 80s. Most famous is their ‘Hi-Flier’ electric guitar, aka, not-an-actual-Mosrite, aka, one of the iconic Kurt Cobain guitars.
They also made tube amplifiers, some of which actually sound pretty great, and distributed several synth instruments and drum machines which are believed to have been built by KORG in Japan. Their Compac-Piano (no resemblance to the sound of an actual piano) was apparently of Italian origin. Here’s a few period adverts for these oddballs. These were all sold in large numbers and are still fairly readily available for a reasonable price.
Edgar Winter with the Compac-Piano