Have you tried using slot-mask.png for shadow mask?
I've made some changes (not on official build yet) to HLSL and one of the things I changed was the order of when scanlines are applied. I set scanlines so that they are applied after defocus instead of before. The result is that you can set scanline alpha to 1.0 and blend the scanlines into each other by increasing defocus. From my understanding this should be a more accurate simulation, and I think it looks better too.
Unfortunately, HLSL doesn't have any general perspective transformations for the screens. This doesn't bother me, but I'm sure there are people out there who want the bezel to be like it is on the right in this photograph:
Realistically, however, we'd really want transforms to apply to the artwork because players orient themselves so that they are facing the screen directly. As I've ranted before, photographs can be very deceiving when it comes to simulating the screens.