I suspect that when the loom was replaced by the previous owner – who incidently used a club endorsed garage!! – they suddenly realised they should have fed the headlamp wiring through the small hole in the headlamp bowl first as the plug will not fit through the hole into the bowl of wired the other way round.
So the easy and quick option is to make the hole bigger to fit the plug rather than to refix that part of the loom.
I must admit i didn’t really want to have to disconnect the headlamp wiring from the loom unfeed it through the wheel arch. Then refix the wiring through the small hole back under the wheel arch to the main loom to put it right.
So I got a feeler gauge to slide into the back of each terminal from the front of the plug. This released the terminals from the plug. So then i fed each terminal through the “hole in the bowl” and pushed the terminals back in the plug – having made sure i had marked the plug to make sure it was rewired correctly……job done!
Found a good use for the old bowl in the garden.