What is this "patent pending" part? I found this part in our LEGO collection, and I'm really curious what it might be, it looks old and says "Pat. pend" on the back. Do you know? Thanks!
It's a tie plate from the original 4.5V train system, specifically from a "switch point right":



http://www.bricklink.com/v2/catalog/catalogitem.page?P=x879cx1#T=C