The escutcheon shown in your photo is one that I have never seen before. Yours has a type of banjo held on by three screws. The one most seen is a 7/8" round escutcheon that has a screw on each side. This release was only used in 1901 and was on the second style of ejectors. This release seems to be on ejector guns in the 6600 serial number range, and I'm guessing it didn't last because the wood screws did not hold the release very well and were prone to stripping the threads in the wood, hence the banjo release in 1902.