This thing keeps presenting nasty surprises. Fuel tank, seat belt,

I'm not so sure where that top photo is taken?

And the bottom looks like something has been chewing on them belts or they were used to tie in building equipment that has chaffed them.

That's from underneath the van. We smelt petrol from the drive and it was actually my 10 year old who identified the source, this is a gumbo'd hole in the fuel tank from what I can see. Have you got one?
Yeah my guess is a dog as plastic is chewed to crap too. It's one of the rear inertia belts. Have you got one :-)