Well. Your camera works better than mine in low light.
I had the same orientation problem with one of my photo's. Photobucket refused flat to keep it the right way up (It's the picture of the wired mirror that's currently upside down).
The illuminated mirror works better for you, as the light would directly fall onto the ignition lock (being LHD). It looks like I'll have to give Roverlike's suggestion of LED's a try.
, I want to thank you so much for your brilliant idea: joining the rear view mirror and the courtesy light. It's fab and was probably much more doable than joining the side arches.
Then, by chance I had 2 LEDs absolutely superb but I blew one of them in a stupid short circuit while testing the mirror! Far much better, as told us @Roverlike
. Hence I have to buy one another tomorrow and swap those weird greenish bulbs for fine & efficient LEDs.
All the work was plain sailing, thanks to all your explanations, your answers to my unstoppable questions and your very clear pictures.
But even I easily soldered the mirror wires with my intermediate one, I couldn't solder anything durably on the plain & flat copper surface of the courtesy light. So I knocked up the three wires, partly thanks to good sellotape tightly fastened and it works.
At last, I followed @Man in the Car
's very good advice and put my wires in the channel on the rear of the mirror mount, and, as the latter was very tired, mid grey-ish mid white-ish & discoloured I sprayed a good layer of black matt paint and hey presto my mirror is now like a new one!
So I'm a happy bunny thanks to you all and this wonderful forum!