Early bay fuel tank identification?

[Passion 4]

Excuse the 'borrowed' pics… but wondering if anyone could ID the year of this early bay petrol tank that has been used to fit in a split screen bus?

Note of the pic where its in the bus. The shape of the bottom is arched to the shape of the shelf it sits on. None of the other bay tanks have this shape apparently?

 

[vwed]

August '71 onwards.
Top one in this diagram:
http://www.jerseylooker.com/FicheDump/EarlyBaywindow/2-002.jpg" onclick="window.open(this.href);return false;
Bottom one is August '67 to end of July '71.

 

[Passion 4]

August '71 onwards.
Top one in this diagram:
http://www.jerseylooker.com/FicheDump/EarlyBaywindow/2-002.jpg" onclick="window.open(this.href);return false;
Bottom one is August '67 to end of July '71.

Brilliant many thanks, now to try and find one…