The following is my response to a question posted on the Type 2 list.  
Thought I would cross-post it onto the Vanagon list since there are more  
Vanagon Westy owners here, and someone may have a better solution than I 
did.
-Ron

>Date:	Sat, 28 Sep 1996 11:20:39
>From:	EXPRES@gnn.com (RON SALMON)
>To:	jmartin@alltel.net,type2@primenet.com
>Subject:	Re: Question about water tank lock
>
>
>The lock was missing on the fresh water tank of our Westy when we
>bought it, but the PO found the lock and brought it to us yesterday.
>He never had a key from the owner before him so I am wondering how
>I should go about getting a key.  
>
>Do the VW dealerships have keys?  Is it expensive to have a 
>locksmith make a key from the lock?  Can I get one of you to make
>a copy of yours and will it fit? 
>
>jmartin@alltel.net

Juli,
Had the same problem when I bought my '85 Westy (except that the lock was 
already locked onto the resevoir, with no key!).  The lock has no key code 
on it, so VW cannot make you a duplicate.  Nor can they sell you a new
lock and key.  You have to buy the complete water filler assembly (about 
$40, I think, from Delta Six) to get a new lock and key.  I went to a 
locksmith, who removed the lock for me but could not custom make a key 
because he didn't have a small enough blank.  However, someone I know did 
bring his key into another lock shop and they made him a copy, so I'm sure 
such a blank is available.  If I were you I'd try a locksmith or two before 
considering paying for a whole new assembly.

Unless anyone else knows of an option that I'm not aware of?

-Ron Salmon