I'm a little late to this party, but the first auto at my first shop was a Starter Oval, 4 color press. We ran lots and lots of 1 - 4 color jobs on it, did our first process jobs on it, and built our own first flash unit (before they were commercially available) for it to run glow in the dark over a flashed white underbase. A good machine, for the time, but too much of a dinosaur now. That's where the 23 x 31 size was popularized if I'm remembering correctly. This was around 1980...
Steve