I have the original article BJP Mar 27 1996 in which Crawley first published the formula for FX-37 and can confirm that the formula given in APUG's Articles section is correct:
Elsewhere the formula is given with 69g sulfite ,which may have originated as a typo, and in the Film Developing Cookbook the formula is also wrong, having a large excess of benzotriazole.
Later, when he was technical consultant to Amateur Photographer magazine, he stated that the potassium bromide could be increased from 0.5g/L to 1.0g/L if the benzotriazole is omitted.He said this was a move to help the amateur as the benzotriazole (originally included for conditions of professional re-use) is difficult to dissolve.The change has no effect on image quality.
He also stated "the closest published formula to FX-39 is FX-37".
In Amateur Photographer Aug 27 2005 he published " a guide to development times of some popular emulsions when rated at their nominal ISO speed" , these times are close to those given by Gerald Koch in the APUG Articles section.