Windows
I prefer the stock round windows because the geometric design of a PA-18 is ROUND. Round rudder, round elevators, round wing tips. Putting square windows in a PA-18 makes it look unbalanced. Plexiglass is heavy, cracks, scratches, fogs etc., the less of it you own the better. My motto is "If you throw it up in the air and it hits the ground, don't put it on." Those stock wings still have to lift all this stuff. The square windows also screw up most of the good paint schemes. Anyone will buy a stock Cub, you have to find a guy that doesn't mind the L-21 glass to sell your Cub to. The plexiglass I use is .100 for the skylight and slider windows, .080 for the "D" windows and upper door. Some guys go .125 on the sky light and sliders and .100 everywhere else. You can do this, but don't need to and it weighs more. Crash