AK 12

The Ultimak gas tube used with the TWS top cover would render a good length of rail on the top deck.

I had a Troy full length railed hand guard on one AK but it was heavy and had to be screwed together on the rifle. This made it pretty solid but disassembly was a pita if you wanted to take off the gastube. Cleaning could be done with it in place pretty much.

RSRegulate makes a bunch of stuff, maybe worth checking those out as well.

Of course the best rear sight AKs are the Finnish and Israeli variants. No top rails on those and limited side rail options.

 

I played with trying to piece together a rear biased side rail mount with a rear aperture sight for AK and it was difficult to get it to align with the front post properly in height.

 

I have a Midwest Industries handguard rail system intended to go on it.

Have seen people add reciever covers with H&K rear sights and various similar designs. They looks good on video but never any followup on how they are a year later after extensive use

 

I am planning on replacing my rear iron sight with a samson rail that wont take up space and is solid as a rock. Friend has them on several of his aks and all hold zero. AK-47 Rear Sight Rail