Elgin 10k GF 15 Jewel Railroad Pocket Watch 49.5mm Keystone Case. Case material-10k Gold Filled. This Vintage Elgin is in good condition with little signs of wear and tear. The movement is running with good balance! The following information is based from The Pocket Watch Data Base established from the given serial number. 1927/1950 Elgin Serial List. See photos for condition. A# Refers to our inventory system.