Help Identifying This Padlock?

[proto57]

Hi: I found this padlock on an island in Long Island Sound (NY, USA) a couple of weeks ago. It was preserved pretty well about 8 inches deep, with heavy black concretions.

It looks rusted, but it is actually brass or bronze, with a rather simplistic faux leather pattern cast in. There are no markings that I have been able to find, of any kind. The curved locking bar appears to be iron, but it is not... it is not rusted, and is not attracted by a magnet. It is about 1 7/8" across, 2 1/2" high, and about 1/2" thick (body).

Dating this would be very helpful, as I am trying to get a range of dates for this dig site. Any help is greatly appreciated.