The fittings on the tank are just plain 10mm non-barbed and I'm using the proper fuel hose mini clips rather than jubilees. They were very tight to slide on so I'd be surprised if it was leaking from there though I'm not discounting anything yet. I've even been round the system swapping out the clips for the next size down where appropriate to ensure a tight seal without having to tighten to the full length of the thread. Even stripped the thread on one by over tightening.
I'm pretty convinced it's coming from the back end of the car now as any scent I pick up around the engine is not at all strong so more likely just residual odor from my injector seal issues a while back plus general oily/engine smells.
One of the problems is once you get the scent of petrol in your nose it's then hard pick up a real leak from just background so I tend to have to decide on a place to shove my hooter then leave it an hour before trying again
