The photo below is of a bell my father bought as part of a large collection of stamps and other items a few years ago. The elderly seller said it was from a steam engine, but had no other detail. The area in New Jersey it came from was served by the Lackawanna. Could this be from a steam engine?

Steam bells were generally about 16" across the largest diameter, and hung from a yoke that swung inside a cradle. Some hung from a bracket or hanger, hard to tell from your photo about the size. Most modern Diesel bells hung from a bracket kinda like what's left on yours. Whatever this one came off of, it probably had an air ringer that swung the clapper, not the bell. Not sure what diesel bells measured, maybe 8" across ? That would be the biggest indicator of what it was on.