While I started collecting baseball cards back in 1957 (& stopped in 1963 when I spent my allowance on girls), I don't know anything about grading but I do have these cards I picked up at a yard sale years ago.  This group includes 1971 Topps numbers  301 thru 350, missing a few.  My reference (a July 1992 Beckett) shows Graig Nettles, Workld Series Games 3 &5, Jerry Koosman, Steve Garvey and Billy Williams as being most valuable.  Cards are in much better shape than the ones I had as a kid  that were flipped, scaled & traded.