Having owned or shot 20 or so #1s, I'll say for a user rifle, the most desirable is a black pad with nice wood, in whatever cartridge you fancy, as it will have a hammer forged barrel
The black pad rifles almost always shoot well, with little fuss. That said, the earlier ones can be a mixed bag.
There have been a few limited models with red pads. If in doubt, check the serial number at Ruger's website for date of Manufacture.
The very early rifles were usually excellent - unless you buy one with a burned out barrel (raising hand). Sometime in the mid-70's accuracy standards dropped, and you would find barrels that were quite rough inside. These can IME be improved greatly with firelapping. All that said, I've never seen a #1B that I would call inaccurate, though I am sure some existed. I think most of the real turkeys from the late 70's or 80's have been rebarreled by now.