I do not understand why you cannot get replacement rotors, I just put a set of 1500 beetle rotors that were drilled 5 x 130 on my type 34 that is fitted with a late model front end, just fitted straight on, the factory manual states that the disc thickness for the rotors for the 68 through 73 is 9.50MM to 9.45MM with replacement recommended at 8.50MM with a minimum of 8.00mm, the difference is the wheel centre ring in the casting which has been deleted on some models. Check this link out and you will see that these fit a lot of models.
http://www2.cip1.com/ProductDetails.asp?ProductCode=VWC%2D311%2D405%2D583%2DA