Prewar National Match adj sight variations?

First Type Stevens Rear sight had the two adjusting screws in the rear sight blade and were used on the earliest Colt MT Woodsmans; Shooters complained of the use of friction to hold and maintain elevation was causing problems and was unacceptable. The later Rear Sight was an improved version with a coil spring tension and other changes that did away with the two friction binding screws that adjusted elevation. Roper gives a detailed description of the rear sight evolution in his book "Experiments of a Handgunner" on pages 56-58. It was his improvement that resulted in the last version that was used on the later Service Ace and NM's. IMO, I think some early rear sights have been modified by using the Roper spring Improvements and replacing the two screws with dummys for appearance. Later versions did away with the binding screws. Fig 14 on page 57 shows a picture of a similar MT Woodsman modified rear sight with dummy screws in place. Jackson.