[N_Force]

I'm not a gun doc. I fix my guns using my sense and feel to make it works. I would say this is fixable. For metal parts, all you need is metal file measurement. Since you've installed and uninstalled 4-5 times. Why not trying another 4-5 times to make it works? As long as slowly doing it step by step, file and check, install and check, and so on.....
but you still haven't told what exactly the problems. Is that the trigger set not smooth or not working? If so, focus on the moving contact points, when cocking the bolt (or open the upper and play around the assembled trigger set) see which are the contact points on those metal parts that needs to be file down. or check for the rubbing area. If you still have questions or not having confidence to do it, pm me since we are in TO area. Good luck.