SOLDThis has felt light seals and sliding retainers. Perhaps useful to make camera back.
$15 incl. postage. I think this came off of some type of polaroid device.
FWIW, I have one of these on an electron microscope camera body (which is now a pinhole camera); it will not mount a Graflok focusing panel and does a poor job of retaining regular double dark slides, but works fine for Graflok accessories like roll film holders, Grafmatics, and the like.