If someone is beating down your door saying this is a rare piece and wanting to give you piles of money for it, I think you should go for it. The posters here have given you their best shots. Without markings, one can't really say anything definitive about it unless you could come up with some historical record that said on such and such date, the good ship Fred jettisoned a cannon of this type in the vicinity of Oyster Bay, blah, blah, blah.
As moderator, I would prefer that you just bring the original thread back to the top with a simple post such as "Is there any new opinion on this piece?" It confuses people to see new but more or less identical threads being started.
