I'm no expert on the old Raleigh Grand Prix bikes, but the examples that I have examined were all standard English 68mm bottom brackets with 24 tpi threading whether cottered or not. But, doesn't mean that this one isn't a Nottingham BB.
As for forks, the three are all different. The Peugeot may be "metric" (25 mm with 1mm thread). Maybe later Peugeots would be 25.4 and 24tpi. The fixed gear is, as mentioned, probably threadless and the Grand Prix is almost certainly 26tpi threads. Forks can probably be moved around if the headsets are moved as well.