Lens for the Rollei is in good condition, some faint "cleaning marks", but otherwise good.

I've been giving the films the same dev time for 120 and 35. I will try developing for longer though.

Having looked at the same FP4 Plus rolls, the 120 backing is clear whilst the 35 is slightly purple/blue. Why would this be different, surely it's the same formulation?

Would over/under exposing cause much difference in contrast and tone range?