VW T4 Project – Interior construction – Removal of all Seats and carpets

I currently do not know anything about the status of my VW T4 interior. Is there rust? Do I need to fix anything before starting to convert the interior to fit the local camper regulations?

Only one way to find out, therefore I started by removing the seats:

So far, so good, but the real trouble might be under the carpet:

in conclusion, this needs to be handled before it means any further trouble.