We've never seen an egg poacher like this one, and have been speculating on the idea behind the flat top handle-less lid, very inconvenient in the kitchen, but possibly very handy for cowboy style cookery! You could heap coals from a campfire right on top of this pan, I think - though we haven't tried it out.
The pan is unmarked, and is made to hold four eggs. The handle is worn and slightly loose - it's made of wood, so we'd guess this pan is probably 1930s vintage.