Railman44, I considered all those features you described but I also considered the fact that the early locks did not have those features but were later added when they realized there were problems. Also the fact that there were once hundreds of “short-line” railroads and the keyhole guard, chain and logo/name would have cost more so they probably just purchased a plain lock as pictured above.
Not all authentic RR locks are like you described. I say that because I once had a Coal and Coke Railroad (
which was purchased by the B&O RR in 1917) screw type switch lock similar to the one pictured here,
http://www.antiquesnavigator.com/images/5-18-006.jpg but which did not have a chain or a name/logo on said. I know it was authentic because it was given to me by my Father who was, by the way, the last surviving employee of the Coal and Coke Railroad and retired from the B&O System in the mid/late 1960’s, …. I think.
Railman44, I had several items of C&C memorabilia, 2 or 3 which I gave to Alan Clarke who authored “
West Virginia's Coal & Coke Railroad: A B&0 Predecessor”, and for which he gave me an autographed copy of his book.
cheers