1877 Lightning Repair

I have a friend's 1877 Lightning for repair. It came to me hollow and I have acquired all of the parts and have learned how to put it back together -as I have found out to get the parts to fit, many times.

My problem is now to get the parts to function together!

Problem 1: It seems that the cylinder stop doesn't return properly. It works freely without the other parts installed. I am hesitant to take any metal from the nose as I hate to buy more parts. It appears to ride up when the trigger stud impacts it, but I am not sure if the nose should be flat along the trigger body or just touch the stud. And it doesn't return when the trigger is returned forward (It doesn't return on its own...)

Problem 2: The sear doesn't move freely and I am not sure what needs stoned or whether I was when I agreed to take this project on...

I haven't put on the hammer spring in play yet, so I am not sure what effect that would have on my existing problems. One more thing, I am not a gunsmith. I have worked on muzzleloaders and other guns, but not double action pistols. Thanks for any advice you wish to share.