Since I have no knowledge of the underside of the car body in the vicinity of the fuel tank, would it be possible to jack up the car, remove the portion of the rivet holding the pipe, and with a hole saw remove the rivet by removing the metal around it. Since the tank is sitting on the rivet, there should be sufficient clearance to avoid cutting the tank. The hole could then be covered with a small piece of metal and epoxied. or a small fiberglass patch.
It seems to me that rivet is a disaster waiting to happen!

NO, that would not be possible absent removal of the rear axle and the heat shield. If you did that, the chances of perforating the tank using the methods you suggest are high.
This is not a huge worry in practice, if you wish to fix it, remove the tank, which is hard work but not difficult. As your tank is fine and no fuel odours, leave well alone, say I; but if you are worried, remove the tank. There is no other way. Your chances of a fuel leak in the engine bay with 10 plus year old injector and fuel line flexibles, or of an accident because of 10 plus year old brake calipers and flexibles, are infinitely higher than anything going wrong in the "trunk". If you ever start to smell fuel in the trunk, then do the whole lot, tank, fuel lines, locking rings, under tank mat, and rivet!
Greg

Thanks Greg. Thought I could beat the tank pulling exercise. But if the rivet hasn't punctured the tank in 23 years I guess I can feel secure. Of course the other side of that philosophy is it got 23 years to cause a hole......
I think I'll just stand pat and wait for the fumes

Well new development in my tank pull... I pressure tested it today and I found no leaks... I did however find a small hole under the rear window that appears to leak right into the tank area. So now I'm thinking the fumes and any gas must have just all been soaked into the trunk mat and carpet and that's where all the smell is coming from. I chopped the rivet off and put down the new mat and new mat/foam on the tank. Hopefully tomorrow I can get it all tossed back in tomorrow. I patched the hole with a blob of 3m tape caulk for now. https://cimg7.ibsrv.net/gimg/www.jag...5a651058cc.jpghttps://cimg0.ibsrv.net/gimg/www.jag...ff0dc2cb20.jpgPuddle in back
https://cimg1.ibsrv.net/gimg/www.jag...7460f137e3.jpgTossed some tank epoxy on rusty spots anyway
https://cimg0.ibsrv.net/gimg/www.jag...664881f375.jpg
https://cimg9.ibsrv.net/gimg/www.jag...ed296068b8.jpg

That water is almost certainly coming from the bottom corner of the rear screen. Where the water is I would also say there is a rust hole at the bottom of the screen as well.

If I were you I'd find the leak and fix it while the tank is out.

Also while you're at it remove those earths screwed to the body, sand the paint to shiny bare metal, clean the terminals and re-install them with star washers, then cover the terminals with sealant, I used seam sealer.

yeah I want to fix the pinhole but I'm not sure the best route to go. It's such a small hole I don't want to sand and mess up a bunch of paint for that little spot. Maybe a small spot of bondo and a dot of paint. Every time I try to fix rust I mess it up nicely. I'm better off with the 3m caulk I have jabbed in the hole. And yes I'm planning on cleaning all grounds.

Where is the pinhole?

right under the chrome rear window frame
https://cimg2.ibsrv.net/gimg/www.jag...45252a2ce9.jpg

That is a rust hole. Bunging it up is better than leaving it, but it WILL spread. I am sorry to say that looks like a rear screen out job to me. This is a pain, but probably, if you are keeping the car, something you will have to face. Go right round the screen rubber/body join with caulk, in the meantime, to ensure no more water gets in there. You will have to remove the tank to fix it properly, so have a good think whether it will be now or later!
Greg

Sounds awful. Ha

Is there no drain in that area? I would have thought at least a little drain would have been possible...

That rust and hole will be there because the rear screen is leaking. I would be inclined to fix it while you have the tank out. I had a similar issue on the LH side and when I pulled the rear screen out the rust was all the way through and the lip needed to be replaced.

When repaired I put the screen back in with a new seal and polyurethane sealant, been good for years now.

Did you manage to get the bright work back into the seal?

That rust hole is about where the drain is. Take a look from the inside, there should be a spigot there or thereabouts, maybe it has rusted out round the spigot, maybe it is salvageable. A tube should go from the drain to the outer wing bottom.
Greg

no the drain is inside the trunk groove that is hooked to the drain tube. This is just a pinhole that shouldn't be there at all

HAHAHAHAHAH, in other words NO, it's still sitting under the bed, 5 years later. In my defense the car was stored at my mothers for a while when I moved 1100km and was waiting for my shed to be built.

The problem with the new seals is they are either made with old tooling or the wrong profile for the chrome to fit properly.

I went through 3 rear seals before I found one that was acceptable, I still had to cut and join it.

Now I am certain it does not leak my plan is to glue the chrome to the rubber with the same polyurethane window sealant.

95% back together. It really is an easy job if you didn't have to deal with gas. https://cimg8.ibsrv.net/gimg/www.jag...6591f3ba12.jpg

If you have no leak in the fuel tank and all fittings are secure, why would you have fuel vapor in the trunk? Could filling the tank or over filling it be the cause? I would not put the tank back in until I found the source of the fumes in the neoprene and mat. Looking at your last picture...That's a plumber's nightmare. Not a criticism; just an observation!

What I don't understand about jaguar is why when there is an identified fault, they don't fix it in the next model year. For example the rivet and the dash panel lights. Even after my cataract surgery I could tell the panel lights were too dim, and that rivet stands up like a honeymoon pecker ready to make love to the gas tank! Another observation!

The only thing I can think is... the small hole that is draining into the trunk is what got the whole mat wet and stinky. I can only imagine the water/humidity mixed with fuel vapors created a stink? Maybe I should've checked the charcoal canister. Maybe the original owner had a fuel spill while changing the filter... I don't know. All I know is, the smell was imbedded in the carpet. I ripped most out. I know that the gas didn't get in the cubby holes and the carpet there stinks like fumes(not a lot but it's there). Hopefully cleaning it all out has fixed it, but of course I'm going to keep my eye on it. The plumbings pretty straight forward, just looks intimidating.