This is how I ended up diagnosing an electrical fault on 771, found a garage where a mechanic owned a BRM and he swapped parts until it resolved the issue
Another MOT pass, apart from a number plate light out, and taking a while for the cat to get warm for it to pass the emissions all is good. She will be doing around 1500 miles over the next few weeks what with the couple of shows planned and having to go up to the north east on a little trip.
Decided it was about time to get 256 started up ready for taxing come April, she fired up straight away after putting her battery back on, always take them off and put on charge every couple of weeks. Decided to do the front brakes, new disc and pads as the front drivers side disc has gone slightly warped which resulted in the brake pedal having a slight not right feeling. Also I thought it would be a good idea to do the belts as they not been done since end 2018. All back together now just going to change the coolant and brake fluid at some stage this week.