I'm the one who was looking into the 5-cyl TD/Vanagon swap. One of the hurdles I ran into was the different bolt pattern on the crank of the 5-cyl engine making for an incompatible 1.6 4-cyl pressure plate/flywheel. Also, as far as I know they never imported the manual transmission version of the 82 Audi 5000TD into the US so tracking down a compatible flywheel/pressure plate may prove difficult (though the 5-cyl gasser quantum may have the same bolt-pattern, don't know for sure).
I ended up selling this engine to a fellow down in Medford, OR who was looking into to putting it into his 5-cyl gasser quantum.
Justin