Yeah I have also read it is titanium enriched alloy on the yamaha website. Who cares, it is a 'filth' tank and I love that autocad program, thanks to it we have a unique tank that Korea is trying to copy.
Looks like Yamaha Australia are happy to answer our emails Wolfman. Might pay to let Duilio know about the website, he struck me as a helpful dude.
Bailey Blaster