Areas that rust - Inner Sills
If your unfrotunate enough to have rotten inner sills then they are still available from VW in Wolfsburg, Germany
As of Nov 08 I bought the left (nearside RHD) inner sill from VW in the UK for about £75. At the time they said it was the 2nd to last one in stock and I know for a fact someone bought another one so they may well be obselete like the right (offside RHD) sill.
Never fear as if you follow the instructions on using the vw-classicparts.de website in the wiki Particularly the ubiquitous Bulley-Hewlett link on insulating and heating a camper van HEREthey have both sills in stock. The offside sill cost me 100.78 Euros which is about £79 and that was delivered to my door within 3 days!!!!
253-801-251 left side member (nearside inner sill RHD) 253-801-252 right side member (offside inner sill RHD
Here's a picture of a vey rare sight in the UK, both sills together. Like hens teeth