Help Tracing a leak in RHD Drivers Footwell...!

[Badger123]

Afternoon All,  I have noticed a dampness in the drivers side (UK RHD) and decided to investigate but I now need some advice...I have removed the carpet and there is a very slow leak that comes in and has soaked the foam underside. so this needs fixing as I suspect its been like this since before I bought it (gggrrrrrrr)

 

 

To begin with I took the cowling off and hoovered then washed out behind the battery etc - the drains seem to be behaving fine...

 

 

There is an area as per pictures (under the VIN) where water pools but does not seem to be seeping away - there is a bulkhead join of solid glue/sealant...maybe that's the slow leak  but  I wanted some advice before I cover everything in sealant!!  See Pics 1 and 2

 

 

There is a "box" / "lid" that seems to retain water around the edges  - it has three screws to remove it but i have no clue how to get to them unless someone has ideas...? See Pic 3

 

 

I poured some water over the windscreen and also in the drains areas and the leak slowly finds its way into the inside of the car, near the fuse box (!)  See pics 5 and 5 - it seems to start by the unused screw hole in pic 4

 

In then took the sticky sound damping off to get a better picture ans as per pic 6 you can see where the water gets too before moving vertically down... Its almost like its tracking a seam or structural beam!!

 

 

A few ideas - i noticed that next to the drains on both sides there is a circular hole that looks to open in the cavity under the car - should these have rubber grommets?  The are about the size of a UK 10pence piece.

 

So, has anyone else had this amount of fun finding this typical leaks?