So had a bit of an accent whilst jacking still kicking my own ass for this. But, its done move on get it fixed. Jack moved went down and I hadn't realised.
Speak to a welder mate, his asked are there replacement panels available? I can't seem to find anything.
After buying the car, and the underneath being in great shape and then having the underneath professionally undersealed. Nothing could have pi@@ed me off more. Wish I had checked before buying. Oh well, you live and learn. Clearly, it has had a leak before, and someone had badly replaced the strengthening bar. But not the floor. Thankfully the passenger side is mint.
Car off to the welders, floor pan cut out they have made a new panel and strengthening bar.
Now I can put it back together, and start fitting shinney new bits to it