LDV Pilot van - logbook - Rust treatment

The MOT document which came with the van mentioned a bit of rust on the front left but I hadn't been able to spot it til I started to treat the rusty areas of the van's body. It's located by the driver's door on the round of the wheel and it looks like it'll need that chemical I used to change rust into metal on the outside areas (mainly around the gutter and the worse being above the windscreen and doors edges) plus a fair quantity of resin to get it back as it was and stop the damage for good. There is also a worrying amount of humidity under the cabin's floor mat which I presume is the result of rust damages and cracks in dried joints. There's a good post on this forum about water leaks (but you'll need to join the forum to read it. Here's the link This, from the same forum, speaks about water leaking through the windscreen rubber joints. Common bug.