Could this be a planer?

[DownNDirty]

I found a wood chisel at the same sight; the only other possibility I can think of is that it could be part of a leaf spring from a wagon. This came from an old home site (home not still standing) where I have found relics from the mid 18th through early 19th century.

 

[nuggy]

Looks like half of a rusty strap hinge to me. Often used on doors before 1900

 

[relic lover]

Close I think it is the latch actually

 

[lastleg]

That would make a great replacement if your address has a 4 in it.