Hi,
for all things keys I’d recommend consulting our list member locksmith and VW key expert.  His site link is below.  He has addressed this issue on list before.

http://www.steveslockshop.com

Eric Caron 
85 GL Auto Westfalia 
Currently with extra gas cap key.

> On Apr 7, 2016, at 10:24 PM, Dan N <dn92610@GMAIL.COM> wrote:
> 
> to could rekey the gas cap yourself .. or bring it to a lock smith to do
> it...
> 
> I had a vanagon with 3 different keys for front, side, and gas cap... a
> real puzzle...
> 
> :-)