Referencing pictures from the Weatherby book, it appears that you have a Weatherby/Vanguard Classic I. I think the dates are pretty close. You do not have a Mauser action, it is a Howa action patterned after the classic Weatherby Sauer 9 lug action except I think yours is a two lug. Someone here will correct me if I'm wrong. I'm not the most knowledgeable but I try. Your rifle was made by Howa in Japan. Some assembly may have been done in Paso Robles, Ca. but for the Vanguards I think that means more that this is where Weatherby was located. The newest rifles will say Sheridan Wyoming.
Your rifle is not old compared to me so stop saying how old you think it is.. Just kidding.. LOL.