Antique brass switch lock, heart shape 1800's

This old brass lock measures 2 3/4" wide and 4" long, and shaped like a heart. Made of solid brass.These were the kind they used on railroads. I believe they called then switch locks. On the lever which pivots sideways It says "TO get key out, Close the lock". Number on the top shank is N2-21 D. No key. Email me if you would like to see other photos.