Charles, black spots could be damp especially if in 120 as moisture can get between the backing and emulsion. I remember the Orwo UT films they used to sell them cheap in AP the price included processing in East Germany I think.
The films were based on the Agfa Neu process from the 1930's I think, I'm not sure they have hardened emulsions so best process between 20-25°C (as I can see you've done)
They were also very prone to fading the dye set is organic rather than synthetic like modern (post 1970's) films.
Mark