There was a period of time (70's, 80's, 90's) when Southbend lathes were manufactured by various companies around the globe. Based on the badging on your lathe, it appears to be a 13" lathe, but trying to identify exactly which model and finding technical information about it may be difficult. Grizzly now owns Southbend and they do have some historical information on their website, but whether or not they could help you is doubtful.
Ted