The gas cap of the sleeve up to 7.66 is provided with a lock
with a square universal key is opened.
At that time it was still no need to hermetically seal everything.
Nevertheless, Volkswagen ran there on windshield
by the engine valve and the fuel valve to be closed if it was with a key
that fit on each bus. In order to protect the hole
in the gasoline valve from damage, there have been placed rosette.
Nice reproduction
OEM part number 261 829 661