I think that'll be a 12x37 - it's identical to the Frejoth FI-900AG (also sold under Dar Sin as the DSL-1237GH) I picked up for the Vancouver Hack Space last year. Of course, it's hard to tell the scale in the photos, and they do commonly scale these designs up. Let me know if anyone here picks this up and wants the manual (it was very hard to track down) and an extensive threading chart I put together, as the one in the manual was pretty lacking.
This is a great deal - the lathe looks to be in excellent condition! I paid about the same, and it took a solid 4 months of all my spare time to clean & rebuild it given the terrible state it was in.