Ruger did make a holster for the ROA but I am not aware of any other "stuff".
And yes, the holsters are quite nice as one might expect.
Talking about investments (which I am not good at) I gave 85.00 for my first ROA in the early 80s. The same time I bought it I also bought a TC hawken in .45 fliinlock for 110.00. I purchased these two weapons in a NATO sporting goods post exchange in Naples, Italy.
I gave the Hawken to my Uncle who died about ten years ago and willed it to my cousin who has it hanging over his mantle now. Took one deer (Pennsylvania white tail 210 pounds and ten points) with it and then retired it.
I gave the ROA to a friend in the German Navy who was in the military exchange program and served in my ship. He wound up as the German equivalent of the Master Chief Pett Officer of the Navy. Uberbootsmann Hanjorg "Yob" Buchheim. The kind of guy you don't forget.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson