Well this is forum on chemistry, but I think it's also interesting to note something on the histories connected with this antique formulas
It's interesting to note, that Koblic, Czech photographer of sound name that time, invented Pextral during WWII. He writes that one of his motives was to make cheep developer not depending on the chemicals like metol which bacame unavailable during the war.
Also he writes, that he wanted simple and foul proof formula which will make photography open to the broad masses of all classes (we are on the dawn of communist power grab!)
Well, he was respected but Pextral formula was nearly forgotten. Even my father prefered in fifties to make D-76 instead of Pextral and after the rise of Foma and availability of Rodinal, people had no need to make their own developers anymore.
ing. Přemysl Koblic made more photographic innovations. He for example designed Epifoka camera for aerial photography. See here:
http://www.liveauctioneers.com/item/988724
Very interesting indea of Koblic is also his "Polygrad - system of continuos change of paper gradation just by controlling of character of light". This is another thing which seem quiet usable even today. Will come to library to get some info about this next time...