L322 rear arche rot

Hi not been on here for a while as I sold the P38 unfortunately now I have L322 (more problems)
I have been poking around with the rear arches and decided they are definitely way past there air best has anybody managed to find a repair panel available for this the bits under the plastic cover can be patched with plate no problem but the bit inside the door would be a bit challenging to make.
Any advice welcome apart from scrap it haha

Due to the construction nature of the L322, the entire side is one panel (External) - front to rear - so you won't find a replacement section, you'd have to fab one up. The Inner sections are in smaller sections, but will need extensive work to strip out the old one and fit the new!

Looks like a tricky fabrication job just cant believe they don't even do a weld in arch lip like they do for most cars . Gap in the market here lol. They are a very bad design how they pack with mud at the back
Thanks for the diagrams tho