Thanks Steve -- I just checked my Speed Graphic -- and yep, there was tension on the focal plane shutter. Now released (after years of being under tension). It is a little relunctant to go from 1.5 to T and T to 0. Should one set the spring tension at any particular setting during non-use (mine has 6 spring tension settings)?
Carbon printing can use a neg of extremely high contrast -- I was using out-dated (1979 and unrefrigerated) Tech Pan. I purposefully over developed (by perhaps 100%, no record kept) in technol.
I find that the opportunity to experiment is one of the great by-products of mistakes like double exposures. When I realize I have botched a roll or holder, it gives me complete license to do what I want with that roll or sheet... new developers, new twists in my processing rituals, etc.