There are several styles of Fechheimer pants, not just the ones manufactured for ASA. Personally, I prefer the non-ASA Fechs to just about any other umpire pant out there. (Dalco, Keen, Smitty...etc.) And I have tried most of them. Fechs tend to last longer and keep their color longer. You can find the Fechs in pleated front, flat front with normal pockets, combos, both pleated and flat front, and of course the ASA style with the western cut pockets.
One purveyor of the non-ASA style pants is
Lester's Upstate Sports.
I do recommend with both Fechheimer and Cliff Keen pants that you purchase a size larger than what you normally wear. If you wear a size 34 daily, for example, purchase size 36 for your umpire pants. Other companies, such as Dalco, you purchase the size you wear.