Oh, I wasn't contradicting you, you are quite right! Anyway, I have been giving some more thought to the Volvo caliper setup. I'm thinking that maybe an original Type 4 front brake disc can be turned down to use as a hub. I want to run the 5x130 Porsche bolt pattern and there should be several ways to do that (later discussion).
With the 4x38 Volvo caliper mounted to the spindle, I measured about 60mm from the wheel mounting surface of the disc to the center of the brake caliper. From the look of it, I found a brake disc that might fit. I would think this Porsche disc would fit over the original 412 rotor turned into a hub as they both share a x130 bolt pattern. I'm hoping only the center hole would need enlarged to fit the larger VW centering ring. The disc is Brembo part 25801. It fits the rear of the '98/'99-06 non-turbo Porsche 911. The diameter is 298mm. The min. thickness is 22mm (Starting thickness 24mm? It isn't listed-not sure if that would be too thick) The overall height is 75.5mm. Subtracting 11mm (half the min. disc thickness) you end up with 64.4 mm. The other unknown factor is the thickness of the center section of the Porsche disc, but I am guess it would be between 3-5mm. Depending on this, it could be very close to 60mm, making it centered in the caliper.
Now, the final piece of the puzzle, would be a 20mm factory type spacer, with the back of it machined to fit the remaining part sticking out of the larger VW center bore. The front side would have the centering ring for the Porsche wheel as usual. Now, just mount the high offset Porsche wheel of your choice!
Now for the bolt pattern issue. The lowest cost option would be to redrill the center of the disc. People seem to be able to get away with this on Beetles, even though there isn't much material in some of the places that the Porsche studs would go into, probably because it is so light. I'm not sure if this is a good idea on a type 4, as it is a heavier car than a Beetle.
Another choice would be to turn down the 914 rotors that have reinforcement welded around the redrilled areas for the 5 lug bolt pattern that I mentioned in the past (if they are still available):
http://www.914club.com/bbs2/index.php?a ... ntry359306
(site may have exceeded bandwidth)
However, it seems kind of wasteful and expensive to turn down these brand new rotors as my aim in using the Volvo calipers is that they are fairly inexpensive and plentiful, at least compared to Porsche parts. Conversely, there would be very little complex or precision machining, and that would mostly be a one time thing. Only the rotors would have to have the center holes enlarged when being replaced, which should be a fairly simple operation.