I actually remounted the screen by exchanging frames. Remarkably brighter.
I mounted an "E" screen and a standard "K" screen. The "E" screen is like your "B" (plain ground glass) but with a grid. Since I have two F2's with DE-1's I use both.
Paul, I was lucky to get a chrome F2 with DE-1 from B&H for $299.00. When I bought a black F2 with DE-1, I sold the chrome F2 to my friend John who can be fickel, John sold the chrome F2 back to me, but now I see owning two F2's especially with DE-1's as being a great-great thing. Just find one and buy it.
BTW the chrome F2 is an early one that features slot head screws, a different film release, and a different rewind knob tip. I'm glad I got the opportunity to buy it back.
I know you are looking for a small camera with a bright VF'er. Look no further, but realize I made the F2 physically smaller by using Nikons smallest lens, the 45/2.8P. Not only does this silver lens look stylish on the sexy F2 body with DE-1 (it will not work on F2's with metered prisms) it is Nikons most contrasty lens (only a few lens elements and all multicoated). I find that the enhanced contrast makes up for the slow lens speed, and find that the extra contrast visible in the VF'er that the 45/2.8P creates to effectively make the F2 appear brighter than it really is. More so that now I have a "K" screen installed from a Nikon F3. Here is the reason you need to buy outright a F2 with DE-1.
I know you shoot a 50 a lot, but I consider the 45 close enough where I consider the 45/2.8P AIS, 55/2.8 Macro AIS, and 58/1.2 Noct-Nikkor all normal lenses.
Cal