Yep think parts for those are virtually non existant but there are many more abroad. I go over to see Stefan a couple of times a year. I take my van across to Mannheim autojumble in Oct so can pick up bits from him. You can also try
www.dk-autoteile.de, they do handmade repair panels along with other early Audi stuff but they aint cheap with the Euro so high and they won't post to UK.
Stu