There is a book on the No. 1 that is considered to be the best collector reference, it's "Ruger No. 1" by J.D. Clayton, editor John T. Amber. It was originally published in July 1983 and a revised printing was released in February 2007. You'll have to search the usual used booksellers and auction sites for a copy at a reasonable price.
Scanning through my copy, the book states that all No. 1 barrels were outsourced, first by Douglas through 1973, and then from Wilson until at least the publication of the book.
Classic Sporting Arms has information on collecting No. 1 rifles at this link
. They have a link on the home page to the Ruger # 1 group on Yahoo, which has many members who collect and will be able to answer your questions. There hasn't been much activity on the group recently, but you'll probably get a response if you join and post a question.