Great find Robert. We ran across Blackstone coin op washers in a Miami laundry in 1957 or 58. I could not see as much of the operation as I wanted because my parents were sitting close to the machines reading the Sunday Miami Herald. This looks to be a newer design, by about 10 years, than the solid tub Blackstones where the agitator lifted to drain the water. I wonder if these had neutral drain. Maybe member Blackstone can enlighten us.
The sad thing about our washing experience was that our landlord told us to go to this fabulous grocery store called the Little Farmers' Market to do the laundry as well as get groceries. Well, we got there after the clothes were done. The laundry was a dream with an air conditioned waiting lounge with television and Frigidaire washers with the Three Ring Agitators, one of which had the round window in the lid. Just before my parents came to get me after grocery shopping, a man came in and started to load that special machine, but the pleas of a 7 year old went unheeded and we had to leave. It was years before I got to see the agitator action.