Jeff,
Before you jump in and get a rebuild, look at the back where the terminals are. There is a raised part of the center of the housing where the rear bearing goes and for your year it should be round. It will have a terminal with a white plastic ring that the white wire goes to on one edge (it's next to the one with the red ring). From Jan 1967 on (the date not 100 certain) that raised round will be tear dropped shaped. If yours is tear dropped shaped, don't bother using that alternator but try and find one with the round shape. When you stated the marking was D4OF-10300- (x), that alternator marking is for a 1974 alternator.
Jim