Just saw this thread!
I often wondered why everyone in this group never commented on these Blackstones. Having seen so many of them through the years, I didn't think that they were so rare.
I never really liked working on these models. To fix the transmission, my father and I had to lift the entire tub and transmission over the top edge of the collector tank. Putting it back in, we had to get the shaft into the center support, without being able to see anything down there. And see the rubber fill hose at the top of the collector tank? No way to avoid breaking that hose in the process.
The hose between the tank and pump was another inconvenience. No flexibility there. Not to mention that the tank would usually start to rust at that point (or in the center, where the rubber boot was).
I don't think that this machine would spin better than later designs. The later designs had the transmission at the bottom of the cabinet. This previous model had the transmission mid-way up. More likely to spin off-balance, and bang against the collector tank.
I did like the stainless wash tub. I saved a couple of those. Not the biggest tub ever seen. Just the right size for carrying a load of dirt, though.
Glass control panel was nice, too, especially on those models that had a fluorescent light behind it.
Very interesting link. I'll have to reread it for accuracy(!).
I love the idea of the triple function filter tray too, very good engineering 
