Great looking models. I should know. I worked at Sikorsky from 1973 and saw Israeli, Iranian, and Navy H-53s come off the line. Even saw them in action in Israel at the Tel Nof air base and knew many of the pilots there. Even rode in a converted one under a NASA contract to create a ride comfort demonstrator which was a CH-53 with a commercial airline interior. Gorgeous aircraft. Feel free to ask me questions if you have any. I might know the answer! You can email me directly at arie1951 at yah00 dot com.