Which one does he have? They still make plenty of them. I have a Shimano N30...which is no longer made, because it was superseded by the NX-30. I can still buy Sturmey-Archer Dynohubs, but they are different from the old Nottingham made ones(which are no longer made). Rumor has it that Shimano provides the insides for the current Taiwan built Sturmey Archer hubs. They also still make bottle generators and bottom bracket mount generators. They are not universally available in the US, but just about every European bike shop stocks them.
Aaron
