The Rover-Landers of BC

So I need to replace the rear floor pan on my D1, I know no surprise there eh.
Should I just weld in a some new sheet metal or is there a place that I can order the pan from?
Anyone done this ?

does it unbolt like the range rovers or is it a welded piece?

there are a couple of discos and classic rovers at the auto wreckers near me i can see how the pans look for you.

Its spot welded into place, and ya if you can have a look that would be sweet.
But its really common for them to be rusted out,so I would be surprised if they are all rusted out by now anyway.