I did a bit of Googling after my post this morning, and found that you can still buy Dia Compe posts and the hardware to convert their other brakes, like the little springs and the D-plate that the spring end mounts into. I remember that another member here had actually rounded his D-plate into an O-plate, so it's nice that these are still available. Those sets should also work with the Mafac brakes, too, using the original Mafac springs.