I thought this looked sorta familiar......
I called my mom and she has one that is smaller and some different, but made by the same company. it is a dressmakers marking guide.

Yes, it is a dressmakers marking guide.
This is the patent. http://www.freepatentsonline.com/D195225.pdf
Whew! That was fun.

Thank you all so much! It was with the quilting things at the garage sale. I had looked on line for information until I was blue in the face, but couldn't find anything about it. I don't sew dresses. Wonder if I could figure out a quilting use for it? Ha!

I'm betting there is some quilting way you can use it. Haven't figured it out yet though.

Oops ... never mind ... I erased my earlier response/guess.

awesome!

wow, what a treasure, glad you posted a picture of it for us