The FED 2 doesn't have a brighter finder than the FED (1). I say that within the understanding that all FSUs vary between examples anyway though. A FED 2 is a bit wider and taller than a FED, not hugely but it's certainly not as pocketable. It's not as tall as a Zorki 4. If you get one with a collapsible lens there's not *too* much size-penalty.
As for thread repair on the FED, you're going to find that a tough one. Are they so bad that you can't just use slightly larger screws? The shell is aluminium so there would be no easy fix.
Zorki: 1e (x2), 2C, 3M, 4, 4K, 5, 6
FED: NKVD, 1g, 2e, 3a, 3b, 4L (x2), 5B, 5C
Kiev 4, 4A
Yashica Minister III
Zenith C, Zenit C, Zenit E
Minolta XG M, Z1
"The way to see by faith is to shut the eye of reason."- Benjamin Franklin