Interesting stuff Peter. I was pretty sure the radio and speaker wiring would be there somewhere as it is shown on the wiring diagram. I am really surprised that the wires were just staffed in behind the foot well side panel instead of being left in the correct position. A bit of laziness there I suspect.
Given that the inside of a Mog (and other places for that matter) could sometimes be considered a damp environment I am amazed that Morgan does not use marine quality screws and other components where corrosion may be a problem. The door hinge screws are a good example, and surely the cost of stainless staples for fitting the upholstery would add very little to the cost.
I am very curious to hear if you think the sound insulation has made any difference after you have fitted it.