The Ken Knull holster has been around forever so it seems. I bought an SMZ (black or brown can't remember) back in the 80's (before the heavy use of Kydex), never really warmed to it, a bit of a quirky design, the leather strap started to crack the last time I saw it, and I just never warmed to it. I can't speak for every government agency (I retired last year from one) but I think the Knull had/has a certain cult following but was never universally adapted or embraced by any one agency or department's gun totters. Today there are so many options for concealed carry.