Thanks Irondragon! I'm hoping someone with AIA can jump in and help me narrow it down but I'm thinking from other numbers in this thread that it's about 1923/1925. I do believe it to be Columbus as well.
Thank you for the reminder to take care of the face! I've had this anvil for about 4 years and have only forged on it once or twice. I got a flap disc on it once, up under the horn, and decided to just let it be its old rusty self, industrial green paint flecks and al!