GSG is a series 80 style firing pin safety, not a Schwartz style like your vid....different animals.
http://www.thetruthaboutguns.com/2012/03/joe-grine/gun-review-german-sport-guns-gsg-1911-22/
You can replace the MSH but you need a complete one, the GSG guts are different and contain the mag disconnect. Dlask has decent replacement sights for these...F/O front and adjustable rear.



























