I’m of the opinion, (and all that follows is my opinion based on 40 plus years experience), that transistor selection is left to ears of the builder. I’m not that familiar with the “American Fuzz”, though it seems a common topology. “Ideal hFE’s” for specific transistor usage is just one of those “builder’s ears” things. The problem with “ideal” components is that they are so often ear-dependent changing drastically from builder to builder. The inconsistencies of germanium are why they got left in the dust with regards to mass production. Even silicon transistors bear inconsistencies – depending on the manufacturer; some manufacturers have excellent (tolerance) or quality control and others do not.
Fundamentally, if a builder is doing one or two “identical” pedals, it’s all extremely subjective or ear-based for getting the best “sound” out of a pedal. If the builder is approaching multiple builds of identical pedals, then this forum is not the correct venue to address the controls of quality so required to assure consistent, quality results.
At the hobbyist level, I find little reward in discussing the actual selection of components for any specific build outside of an academically controlled environment. There exists too little of what levels of awareness\knowledge\experience the other participants possess and discussing how to test specific values and parameters of specific components is simply a matter of academic referencing.
In any case, I hope you don’t get too mired in the imperfections of component manufacture so exposed by the science of electronics. Rather, I hope you find what I consider a joyful experience in the exploration of the possibilities that (component-swapping) can bring.