72 Sierra Grande I lost my way

[saddletramp]

Evening Im lost ive got my cab stripped down i have to replace my inner cowl its rusted pretty bad right where the fenders are attached on both side,s i have that one off im cleaning up all are,s under it but one problem ive lost my marks i made to get it in the same spot as the original so my fenders will line up can any one tell me how to get it in the right place the spot welds dont match up with donor cowl im useing off a 71 any guidence will be appreciated. Thanks