Off the shelf, the
DSA hooded match sight is pretty nice. I have one on my Imbel FAL. It fits tight and gives a nice sight picture. The arperture might be a little small for low light shooting, but the hood and the fact that it's so close to your eye, helps. You could always drill it out a bit if it's too small. It was a drop in replacement for the original rear sight (which wiggled like crazy).
I agree with Bwana John about turning down the diameter of the front sight a bit. That's something I've been meaning to do with my Imbel.
I like that rail mount, however, I think that you would have an issue with the front sight being too low.
Right. That's why I say mount both front and rear sights on the same rail (you'd probably need a longer one than I shown). They do it with AR's all the time.
Another option might be something like the
rear sight on the Kel-Tec SU-16C mounted right on a railed top cover (maybe with a taller FAL front sight like one from an Israeli or British FAL). Unfortunately, that particular sight lacks a windage adjustment, as does the FAL front sight.
How does the accuracy change on your FAL with the scope mounted on the same plane as the barrel? What kind of MOA do you get with it?
With surplus, it's shoots about 2" groups horizontally at 100 yards, but it strings vertically about 6-8". I've been researching that. It's a common issue with FALs. Some folks have fixed it by modifying and loosening the handguards to keep them from putting pressure on the barrel. Some have played with the gas piston length and spring rates. Some say it's a magazine issue. Some have even played around with bolt/carrier fitment. I need to get back out to the range with the handguards off, the gas system turned off, firing single shot, loading through the ejection port, to rule those out.