It seems that you never can judge a book by it's cover.

Talk about a dirty fuel tank !

that box of metal looks heavier than the fuel tank... lol

Lee

what is that? rust?

When it was wet with fuel it looked like the rustyiest tank you had ever laid eyes on, but all that junk dried and showed it's true colours.
The tank had a liner/treatment of some sort fitted, well I think it didn't like the Fuel as it went to sh1t and blocked everything....

Funny as the car is so beautiful, and the owner was telling me just to put a new filter in and eventually all the dirt will come out

haha lol. I initially thought is was charcoal