What the heck is this???

What do you call them and more importantly, where can I get some more! I swiped this picture from Vintage House Parts. They referred to them as knobs (pulls) but that's not what they are for. These little brass doo-dads are stamped with "Curtis 1866" and have two brass halves and a brass screw to connect them. These are to hold in the inserts (either glass or a screen) in my storm/screen doors. Each end goes on either the inside or outside of the door and their wide enough to hold in the glass/screen insert. Problem is I don't know what they are called. I've checked all of the vintage screen door companies that I could find and they use something else now. I summon the houseblogger community to leverage our collective knowledge and to do my bidding