Cal,
First of all, car is looking good Nice one.
The connector in question was in the car when I got it and always wondered what it did. I may be very wrong but I think weeb said it was to do with either an arial or mobile phone. I have a feeling that a cable attached to it runs into the boot and should be lying loose under the boot carpet. Could be totally wrong though!!
I also think that there was a connection from the battery that ran into cabin just behind the centre console and ran into the drivers footwell. Was a black, spiral lead. I am sure weeb used this to power a Road Angel as there was never a cigarette lighter. I never used it and tucked it under the drivers footwell mat.
Hope this may be of some help!
Pedals