Brother Phil-that was the first type II ejector escutcheon used on the earliest guns fitted with Type II ejectors. I wasn't deemed as sufficiently strong, so wasn't in production very long before the base of the Type II ejector iron was widened/strengthened and the escutcheon lengthened to provide an anchor point for the front screw and became known as the "banjo" escutcheon. I wrote a piece about this device years ago for the LC Journal when the Journal was no more than a few pages staples together. Interestingly, this early round escutcheon is the same diameter as the Bakelite doghead insert.