Need some advice on rear sight

New to the forum, first post. Been lurking and learning for awhile, really grateful to all the passionate M1 Carbine owners out there. 

I own two M1 Carbines that I believe to be relatively original. They were both given to me by relatives who did not provide much info on them. I've decided I have to part with one of them, but I have a few questions for the forum. 

One is an Underwood barrel 3-44, with a National Postal Meter Receiver, serial 1525xxx, stock has oval shaped oiler cut, lower slide opening, stock is marked with a P-J, rifle has a lever safety, type 2 rear sights, "M" etched on the mag release, and a bayonet lug. Those are the highlights. To me these various features indicate it has at least been reconditioned or rebuilt. 

The other is an Underwood 11-43, with Underwood Receiver, serial 2781xxx, stock is marked RMC, I-shaped oiler cut, higher slide opening, and every part appears to be Underwood sourced, with the exception of the trigger housing which has a Q-NL on it, but I think this was common even for an original. It has a type 1 rear flip sight. 

My questions: I feel the second is definitely the more valuable of the two and that is the one I intend to sell, I have completed the data sheet (mostly, I did not take apart the bolt). I am wondering if anyone disagrees with this, or if there is anything I have not considered? 

My second question, the type 1 rear sight on the 2nd carbine has come loose. I have no idea how to "re-stake" it and I get the impression that I can damage the dovetail if I tried and failed. I would lean toward applying some Loctite if I was to fix it. My question for the forum is if you think I should even do this if I am selling it? The prospective buyer may know how to re-stake it or may prefer to set it themselves. How negative would it be if I offer it with a loose or even separate sight (the sight is original, to the best of my knowledge). What does the forum think? 

Thanks in advance, and Happy Memorial Day, everyone.

Ok, thanks. The 1st pic isn't good enough to tell. The other two suggest to me it's ok, Looks like it has tooling marks on the one side?

PS: how the receiver dove tail is staked can tell more of the story. Is it little chisel marks where the sight used to be or crater points? Some have both and some have none.

That sounds like it's just flip staking then and the chisel marks are typically on the right side of the flip's after install. The S faces to the left side if the receiver. Point the muzzle downrange with the receiver toward your stomach. Take the sight in your right hand and insert it in the dovetail from the right side, with the S facing the left side. If that's what's too loose after sliding in there are ways to correct it. if you're selling I wouldn't do anything permanent. Some of us have had a little experience.

The type II sight would have round crater stakes.