When you say "not factory brass" do you mean they use Ruger brass grip frames but won't letter as being shipped so equipped, or they use "Non-Ruger" brass grip frames?
Very late '58 or very early '59 if shipped in "proper" order. Type 2 "Roundgate" with straight-slot steel ERH. Change from round "dimpled" button to round "flat face" button somewhere after 126435. Could have had walnut panels, as well. Info from RENE Referenc...
Somebody has to get this ball rolling . . . I admit to having "one of (almost) every Ruger Old Model". I shoot them all. My very first Ruger was a Single-Six RSS5X that I received for Christmas in 1962. I still have it, still shoot it. Over the years though, the .45 Blackhawk has become my...