These were called "9-inch Special Metal Turning Lathes", made into the early 30's and were a low cost
O series based on the 9 inch Junior parts (not finished). Probably phased out 1933 or so, because the
number 20 catalog number was reused on the 9 inch tool maker. There also was a Special number 19 which
was a 10 inch lathe. It had a lead screw and reverse and IMO was the lathe Sears sold as the Garage Special in the early 20's, South Bend advertised these lathes for small repair shops and service stations for light repair work. The wide bed lathes progressed in improvements up until about the fall of 1938, when the 9 inch underdrive bed was recoded for the Heavy 10, that bed was UD100 and the new code was UB100. The next revision was 1942 when they increased the finish area ahe side of the rack and bolted the headstock directly to the bed, and the "10" South Bend" was cast into the bed, that was UB101.
9 inch lathes that some call the Heavy 9 were made into 1939, but most are T series, The only catalog number I have ever found that could be what we would call the Heavy 9, is a 8159 Toolroom 9 inch wide bed (9 inch, 1 inch collet lathe). It would have to have side oilers and have the S series superfinished spindle. In my South Bend catalog card files, this is the only number that is not marked as a T series, but, it is not listed as a S series either as the Heavy tens are.
Steve Wells
I picked up the exact same lathe from a neighbor. I thought, like you it was missing parts, but came to realize it was supposed to be that way. I'm in the process of cleaning it up and getting it set up. Have you found out any more info on the lathe?