Just an update
I removed the seal today, the lip was quite rusty so I ground back and treated all the rust and refitted with some silicon adhesive, most of the water was coming in through the aerial as it was loose, I removed the rubber boot and put a bead of adhesive silicon around it, now all tight and no leaks that I can see
I still have not put the carpets back as they are drying out indoors, I also bought a couple of moisture traps , one in the boot and one in rear footwell, so soon the rear screen might stop fogging up all time!