As you probably know, you cannot get the wood from Ruger. The stock is a "replace at the factory only" part. And, they have refused to put No. 1 wood on a No. 3 at the factory.
I got the first one from Great American Gun Stock Co. It was unfinished and 95% inletted. It was not cheap, but the wood was nice. The second one was an old Bishop stock that I got off of e-Bay. It was half as much, but was plainer wood. It was also unfinished and 95% inletted. The auction websites have No. 1 stocks on them on rare occasions. When they are, they don't go cheap. The fully finished takeoffs sell for more than the 95% finished ones. I know that I looked for about 6 months before I found the second one. They were both listed as No. 1 wood, not wood for the No. 3, but they fit well. There are a couple of other places that list No. 1 wood, but I don't have them here. When I find them, I will post them.
Neither one was hard to finish. The thing I have learned from fitting other 95% stocks is DON'T USE A MOTO-DREMEL TOOL. Use hand tools only. The moto-dremel tool will get you into trouble faster than you can stop it. Get stock fitting black paint from Midway or Brownell's and use it. It is messy, but it shows you where to take off and where NOT to take off. The amount of wood you have to remove is fairly small, but it is in several different places (sides at the front, around the top and bottom tang, at the rear of the receiver where the bolt screws in, etc). You need to find those places (with the stock fitting black) and remove them wherever they occur. Once that is done, sanding the outside and coating it was several layers of Tru-Oil (with light sanding in between) is downright easy.