It's a 12" lathe, I had one just like it I sold a couple years ago, It's NOT a 6", I've had one of those also, completely different.
They made 10" and 12" models in this style, the visual clue between the 2 is the raised tool post area on the compound, on a 10" the top tool post slot was at the same height as the rest of the compound rest. The 12" compound is raised 1" as in the picture.
The lead screw reverser is correct also.
This one has the plain bearing spindle, later models had timken style bearings.
I got $700 out of mine 2 years ago with 3 and 4 jaw chucks, a quick change gearbox, and a nice heavy metal cabinet.
People get all excited about the QC gearboxes, yet in reality you don't have to change feeds very often, and changing is not really a huge hassle.