Hi, Irod,
The longer barrel provides a long sight radius for those who prefer that. The shorter barrel allows the gun to balance more back in the hand, which some shooters (I for one) prefer.
S&W used to have an option called the extensible front sight, which fit on a rail dovetailed into the barrel and held by allen screws. Loosening the screws allowed the rail and sight to be moved forward beyond the front end of the barrel, giving a long sight radius without the extra weight. AFAIK, that has been long discontinued.
The fact is that formal target shooting, of the kind the Model 41 was designed for, is not big in the U.S. today. Even when there was more interest, there were not a lot of aftermarket goodies for the Model 41, mainly, I think, because it was so good to begin with.
Jim