Just a guess, but perhaps the cylinder came with the bbl and were both from a 1950 and used to update the 1917 or rebuild it from an abused frame.

The reddish color of the reblued cylinder reminds me of the later mfg ones. That and the ejector rod end being the later style.
The cylinder may have come with the ejector and ejector rod in place as they often do when found as 'parts'.
Maybe the crane came with the cylinder too. Looks a little newer than the rest of the frame in the pic but that might just be that,,the pic.

A check of the ser#s on the back side of the cyl & the crane will tell in a hurry if they are orig or replacement.

As far as the gun itself,,the grips look like a $200 set to me unless I'm missing something.

The pitting on the frame is not really that bad from a refinishers standpoint if you wanted to re-do it. Not saying it'd be a money worthy effort from a profit making angle, but it certainly isn't something that is in the 'all is lost' catagory.
A belt grinder and capable guiding hands can remove easily having the surface back to WW2 rebuild look in no time. Going further to a higher polish for an orig look takes more work and time but that's just the nature of the trade.

It's a great project gun to re-do or rebuild into something else. Most N frames are. Lots of ways to go or simply go easy on it and fix the lock up issue at the front and any small cosmetic issue and then just shoot the heck out of it.
All depends on what you want it to look like, what you can stand to look at and what you want to spend.

Just my thoughts.