Well, if you don't have much in it now, you can probably fix it for a $150 in parts maximum if there isn't much wrong with it. The cylinder not turning means that the cylinder hand is not coming up. Most likely it would just need a new hand or trigger. That model actuates the hand direct from the trigger as near as I can see.
Here is a parts diagram for the pistol.
http://www.coltparts.com/pt_1877da.html
Looks like 0000 steel wool would strip the remaining finish with no problem, then, clean all the parts in a bath and you should be able to blue it. Getting it all nickel finished would be fairly costly in comparison. Ultimate value won't be greatly increased with whatever finish you put on it but bluing can be done inexpensively enough.