Help to ID an old Triumph petrol tank please?

www.thunderin.co.uk

There are a few pics of the tank on the link. I've had it in the shed
for YEARS! I started to spray it a metalic silver back in the late
80's as a demo and got as far as the clear laquer, but it never got
sanded down and finished for some reason or other. It's solid, no
holes and has been kept in the dry for 99% of it's time with me.

Under the paint it has holes for a tank rack, if that helps narrow it
down. I'm putting it on Ebay soon unless someone here has use for
it. Thanks.

 

Looks very similar to my '72 Bonneville tank but a lot of trumpet bits
are interchangeable.

quite possibly, my US spec 2 gallon has a leak and my UK spec is a bit
tatty. I'll measure up tomorrow and we can perhaps see if it's the
same fittings.

 

It looks like a T120 Bonnie tank, with the centre seam and centre
fixing. The earlier 650 and the 500s/350s had tank rack holes and
centre seams, but were fixed by bolts to the underside of the tank,
and the T140s didn't have the centre seam nor tank rack holes.