This Gruen Guild just came in today. It has a Cal.415 movement (18000 A/h, power reserve 48h) and is a 10K gold filled case. According to my quick Google search, Gruen used the "Gruen Guild" dial during the 1920s and 30s. The case is in very good condition (no wear through) and the movement is very clean and running very strong. I paid $26 for it.
Thanks for looking and any other info about this watch would be truly appreciated! - Hiro