Lomography 'make' both colour and black and white film. Their black and white comes in two flavours the 100 speed called Earl Grey is Foma 100. The 400 speed, called Lady Grey, is TMAX 400. The film is rolled and packed by someone else using shoddy backing paper which transfers the dots and numbers.
If you can get the film on to a reel and then look at the backing paper it might give you a clue as to which film it is. I've only used the 400 and I can tell you that the backing paper is slightly thicker and fibrous than paper from any of the big manufacturers. It may not help you if they use the same paper for all their 120 film but if it doesn't sound like this, then it might not be the 400 film.