14 x 125 (1.25m pitch) is French threads although they can be successfully retapped to accept 9/16" pedals and this was common practice.
49Ds were made in both French and English threads but not always stamped with which thread they are.
Early Stronglights, including the 49D, require a 23.35mm extractor not the common 22mm one or the TA 23.3mm one (which might work but will be a loose fit and risk stripping the threads).