I recently bought, what I thought was a vintage Brown & Sharpe Protractor, but now that I have it in my hand, I do not see any marking or makers stamp but every other picture of a Brown and Sharpe protractor that I can find looks close but there are always a couple of differences. Looking at others this looks more like a Lufkin protractor can anyone help me identify it? I've never owned one and I don't want to start the eBay refund process unless I'm correct that the seller lied.