Howdy and welcome. A couple things. The '75 Remington is known as an "Army" revolver, and it is single action, but the term "Single Action Army" generally is referring to the Colt. That might make for a little more specific search for you. Other than that, I can only say that the model you are looking for, the 7.5" blued in 45 Colt (? you didn't mention caliber, .357 or 44-40 will be a little harder to find) is the most popular version of that gun and there are more of those out there than other versions or finishes. So keep looking and you might find a used one. As you have surely noticed, new guns of most varieties are in short supply these days.