Here we have another "What is it" for you to ponder.
We saw this one hanging on the wall in a Quilt shop in Chamberlain, South Dakota. The folks there didn't know what it was and we don't either.
You can get a general idea of size from the two pictures below. Sorry about the poor focus in the picture that has my
hand pointing at it. I took it with my cell phone.
I saw no identifying marks anywhere on the thing. Here are 2 views of it:
The whole blade assembly seems to have been stamped out of one piece of sheet metal and then each "blade" was
twisted 90 degrees.
The teeth seem to be shaped like isosceles triangles, not "hooked" in the cutting direction like regular saw teeth.