Good stuff Mr Shed. It looks like you're getting stuck in and I'm looking forward to more updates.
If it's any consolation, what you have found seems to be normal P6 rot spots. When I patched my sills up last year, the o/s was certainly worse than n/s on my car (I'm thinking there must be a scientific reason for this - :idea: mabe o/s is subjected to more salty road spray from oncoming traffic that get's forced under the sill covers??. Like a few others on the forum, I just made up repair panels. Though, plenty of others get the repair sections and often just cut them down to the size needed.
Those jacking points are a bit of a pain. I repaired one on my car but I can understand why some folk just opt to get rid of them.