Stage 1 V8

I need to replace all the fuel lines that a previous owner installed when fitting a second tank. Incorrect plastic had all hardened. In sorting these I found a small tank behind the R.H. Rear taillight that is connected to tank breather tubes. I cannot find any info on its purpose.
Anyone have any info?
Cheers
Paul, Gold Coast, Aus.

Pretty sure it's for emissions. Mine has one on the back of the cab.

So you have a Leyland Australia Land-Rover 3.5?

As per the last pages in the main parts list it is the vapour tank. Part of the evaporative loss system.