The good news: I managed to get an inner headlight from Barry McGrath the Acclaim Guru. How, you ask? He had a MK1 2.5PI estate restored for an obscene amount of money and in doing so he fitted halogen headlights in place of the original sealed beam units so he had some spare. The Dolomite 1850 uses the same headlights as the Triumph 2000 range so it was just a matter of fitting it and now I have fully working headlights.
The bad news: That's all I got done last night. Snowdrop's CD player is dead and tried the take half of the electrics with it. Despite dismantling the unit (to get a CD out) and doing a few tests with my multimeter I couldn't find the problem so I'll have to bin it. I have a Panasonic radio/cassette which I can fit in it's place. I need something as it's the most important driving accessory and wires sticking out of the apertuere is a bit unsightly. I can hook up my MP3 player when it is done.