The model back then was typically based on the swing dimension. In other words one with a 15 inch swing would be a Model 15, and so on. Short of paying to get a build card on it, it's hard to tell a date exactly, but when I called in and talked to one of South Bends people, we estimated mine was built around 1925. That said, check out the web site and you should be able to ID the model a bit more precisely.
As far as the value, I a similar one, with a 15 inch swing, and an 8 foot bed, that I sold about 4 years ago for $1500. I had shimmed and bored the spindle bushings back true, and set the clearances on them. I also sold it with two chucks (independent 3 jaw and 4 jaw), all of the change gears, a follow rest, a milling vice, and some other assorted tooling. Based on what I see in the pictures, I'd guestimate that one going closer to the $500 mark, or less depending on actual condition, and that's to someone who just needs the larger swing/bed length, but not the expense of a more modern machine to get it.
Mine was originally a flat belt drive, but it had a frame mounted off the back, that was built to carry a 1HP three phase motor, that drove a jackshaft via a V belt, and in turn drove a flat belt to the spindle.
As far as accuracy, once I got the spindle bearings trued up, it would easily hold .001 anywhere I set the carriage. I guess I just got lucky because this lathe hadn't seen much use in it's life. In fact, the man I bought it from said it was in the building he was renting when he have moved in nearly 40 years before, and other than polishing a shaft, or turning a rotor here and there, he had used it very little.
With all that said, if your just looking to get rid or it, don't be afraid to take whatever you can get short of letting it go to the scrap yard. The way I see it, it's a piece of history and, in my opinion, mechanical art, and they definitely aren't making them any more.
To be honest I miss the 'old girl
South Bend Lathe Company