I'm behind on my formal updates but I thought I'd jump ahead with some good news: the Charger passed its MOT on Friday!
Very happy, to say the least. After sinking so much time and money into it I was concerned that it might turn out to be a bit uninspiring (or have further hidden issues), but it drives far better than I ever expected. It's got some serious muscle, too!
Didn't get to spend much time with it this weekend, though, so I'm looking forward to next weekend already. I'm not putting any more miles on it until I've changed a few things, mind - primarily the tyres (which look immaculate but are old, so I'd rather err on the side of caution) and the radiator hoses. Would like to change the oil again, too.
Going to get back to the keyboard soon, as well, and write up the updates leading up to the test.