Lots of fact, opinion, and speculation in this discussion.
The stainless-steel ROA appeared before 1982. Possibly 1976 being the first. I have one manufactured in 1979. I have also seen so-called "Liberty Guns" with the 200th year of American Liberty roll mark on them. Ruger designed the ROA to get into the emerging Cowboy Action Shooting activity, along with the renewed interest in muzzleloaders and black powder shooting.
He wanted a solid, trouble-free revolver, of modern materials, using as much of the components/parts of the Blackhawk as possible, while maintaining a historic or traditional look. There is much speculation, but Ruger was a firearms historian who studied many designs and favored some over others. If he wanted a historic or traditional look to his Old Army, it
may have been this:
https://whitneyrevolver.com/
The grip frame, and many of the internal parts or components are Blackhawk. XR-3 RED grips will fit nicely on the ROA.
It is true that Ruger simply used .45 caliber barrels.
I have never heard that Ruger discontinued the ROA because of conversion cylinders. Not to say that it might have been a factor or concern, but most firearm models are discontinued due to declining sale numbers, and/or production costs.
History doesn't sell current firearms, as DuPont said when they owned Remington.
The ROA, NM Blackhawk, and NM Super Blackhawk are mass-produced, investment cast revolvers. If you have ever visited the factory in Newport, New Hampshire you will see the entire production and finishing process, along with the pride of product that goes into their final assembly. They are a strong, rugged, and reliable revolver, and great value for the money.
What they
are not is hand-fitted and tuned like a Colt SAA.