Ok, not exactly in order,
My Hassy won't work either, if the dark slide is in.
The "black crud" looked like a lot of black silt in the pre-soak water. The pre-soak water was entirely black at one point, but never clear.
The index numbers and the film type, maker, codes, ect are all on the two edges of the film as they should be. Nice and dark, too.
I took the back off and fired with the camera pointed at a light; both shutters front and rear fired as they should.
I just shot a roll of color film and put it in for commercial processing. I am awaiting the results with baited breath.
I could have done that with Ilford except that I am out, and my source is 75 miles away. The only 120 available here is Fuji color.