<<Is there a difference between the "Older" and "Newer" locking gas
caps?
A friend with an '87 Westy uses his ignition key to open the gas cap.
On my '84 and my '85 ... I can't do that. They have shorter "different"
keys from the regular VW keys.
Mike>>

My 85 fit the 87, and the 87 fit the 89, and the 89 fit the 85 so on and
so forth.

And it's always been just the ignition key that fits all, be it old,
new, used and abused, whatever.
The difference was zip.

If the cap was a genuine VW issue cap.
Not some list vendor rendition of such.