I subscribe to Old Cars Weekly. They also print Old Cars Price Guide. I get a price guide about every 3 months. I think I got a special "offer" at 12 bucks for it. I usually subscribe about every other year to it. But I do take the Old Cars Weekly paper. It comes every week and has some good stuff in it. Plus, it list the selling price of the big auctions and things.
They have followed auctions and such for over 40 years and I have found them to be pretty much "on the money". But, as I tell everyone, its a GUIDE. Personal inspection and condition may warrant more or less.