the flywheel marks are usually accurate, as they can only be fitted on 1 way (well, you can force the flywheel on wrong) As dan says check piston #1 is at the top when you have lined the flywheel punch mark up, you can be 99&% sure its spot on then, especially if its an oem flywheel. If you have the punch & diamond marks then its an oem flywheel. (new ones dont come with the diamond mark you gotta make your own)
the cam marks should be ok, as long as the sprocket has been fitted the right way, and ignore the intermediate shaft mark just check the position of the actual dizzy.
If you lined the crank up to the diamond mark its not a big deal, just loosen the tensioner and move the cam sprocket when the bottom is lined up to tdc. the rotor arm only needs to be close enough that the car runs, you should fine tune it with a timing light anyway.