Exposed and unknown 120 roll film

While searching for some unrelated paperwork, I've stumbled across 5 rolls of film that I'd completely forgotten about. They are all exposed (one 35mm cart, and four 120's), and all are identified by their brand - except one roll, which has nothing but the unprinted black backing paper visible. It has been several years, and I honestly don't remember much about their photo content, let alone when/why they were tucked away. My first guess is that the all-black 120 roll could be Shanghai GP3 100 ASA, but it would be great if someone could confirm that, assuming you've used some and know the packaging/paper it uses.

If it's still unknown, then I'll probably send it in for processing anyway and mark it as GP3. I'm no longer set up to do my own processing to snip off the tail to test, but I suppose since I haven't missed the shots thus far, the cost of dipping a single roll will teach me to pay attention!