[Texasrocker]

I have also repaired many vintage Philcos from that era. I have never seen a shadow-meter "gasket" of sorts as in your photo. Im sure Ron & Chuck will be able to clarify on the identity of this part if it was original and needed in some of the Philco sets. I learn something new everyday checking in here indeed!! The shadowmeter was a wonderful-invention indeed! Not necessarily "accurate", and otherwise needed a "mask" -gasket? If I ever need one of those, just bet I can use some home window-AC installation gaskets to make a good repro with my olfa-knife!?? Havent tried that yet! Next best invention to the orig Philco bake-light block condensers? Reckon? (hee hee)