Neat find!
From the time that refrigerators came into homes there have been various attempts to make ice cream in the freezing compartments. I have an ice cream maker packed away somewhere from the 30s or 40s that is sized to slide into an ice cube tray compartment since many early refrigerators only had freezers that made ice cubes. It has a motor that turns two dashers that run the length of the tray. I has a cord with a soft, insulated sheath so that it can run through the door seal to be plugged in outside the box.
I'll tell you what makes quick, delicious and very smooth ice cream: instant pudding. The ingredients approximate a cooked custard so it freezes with a beautiful consistency, not at all grainy or full of ice crystals.
My grandma used Junkett freezing mix and beat the mixture in her Mixmaster, then put it in a tray to freeze. When it was slightly set, she beat it again to incororate more air then put it back to freeze. She did this with a Gibson refrigerator that only had a freezing compartment across the top that held a single shelf of ice cube trays. If we ever went and bought ice cream, what was not eaten as soon as we got home was spread into an ice cube tray and put into the freezer.