Might try @cmshoot
He's a certified armorer who works at a place that works on guns
More importantly he's a Marine so he can fix anything...with a rock!
Are you sure it's not pin and welded?
If it is, it will need to have the pin drilled out before you can remove it.
Is it a 14.5" barrel? If it is and it isn't a NFA gun, it's pinned and welded.
Looks good! Now you're hooked and will want to build another one 😁
Plus one on the Streamlight HLX recommendation (when on a budget). Surefire, Cloud, ECT are brighter and more durable, but much more expensive. https://www.streamlight.com/products/detail/protac-rail-mount-hl-x
The keymod rail...
Make sure you put the hammer spring in the right way or you will get light primer strikes. It installs backwards just fine. Even gives you a better trigger pull weight 😉
Just a suggestion. Remove the bolt from the carrier and see if just the carrier will go in. If it does, I would suspect something with the bolt or cam pin. If you really want to get into it, if the carrier goes in fine by itself, try changing out the bolt and them the cam pin to see which one is...
So is the issue the wallowed out rivet hole at the front of the reveiver ( next to what I think is called the trunion)? Not an AK guy, asking to learn.
Eotech isn't doing the buyback anymore, but if it's a sight they still make, they will do what they call a service that will bring it up to current the revision level. I sent them a 2010 xps2 and $79 and they sent it back in 3 or 4 weeks with everything replaced on it but the base and hood...