Front footwell leak found - how to cure?

[taylormj4]

Folks,
It's been driving me nuts for months but I've finally found out where the water is coming into the footwell from.
Thought it was door seal or inner wing seals around clutch reservoir etc but it is actually coming in between the two layers of carpet on the outer footwell wall next to the A post. I pulled up the lower part of the carpet and found quite a large hole in the fibre glass of the footwell side wall (inner part of the A post), which appears to be the access to the lower door mounting ?
The water is pooling just below this hole.
Heck of a draft coming in through there when I'm driving too now I've removed the carpet.

The question is where can it be getting into the A post? Can't see the lower hinge without removing the door.

The car was recently stripped for respray (including doors off). Is there a seal around the door hinge maybe ?
Can windscreen seal leak into the A post ?

Thanks.

[N7GTX]

I recently replaced the bottom door hinge bush using that access hole. There was no seal between the hinge and the bodywork so if there is a serious draught coming in its unlikely to be a windscreen leak. I'd be inclined to follow the hollow forward to see where it meets the wheel arch, maybe using a small mirror on a stick and a torch?