There is one other trick I use worth mentioning. I have a very small sheet of pre-cut squares of masking tape. Each time a new roll is loaded into the P67, a small square of tape is taken off, and details are written on it and attached to the back of the TTL prism. At the end of the roll, and irrespective of whether the roll is Fuji or Kodak, this small tape square is removed from the prism and attached to the end of the film roll. This assists me in keeping track of roll file numbers and when the film is back from the lab, it has that piece of tape on the sleeve that tells me immediately which roll it is. Unsurprisingly perhaps I have not had any rolls mixed up in numbering/filing using this method and fiddly TMax rolls are quickly tamed.