First time poster. I am curious if anyone here can help me identify the dial of this Omega Seamaster 300? The dial looks original, not repainted, but 300 is missing. Maybe this is a some kind of Prototype dial? Omega Seamaster 300. Case:14755 -2 reference with cal. 552 automatic movement. Early paten pending ref. 18269XXX movement serial number. Thank in advance for any help. It is much appreciated!