I'm definitely making progress now - I feel like I'm about a third of the way through the M. I'm having to be a bit careful of wear and tear on the thread, but I do feel like I'm getting better at this satin stitch thing. (I'm not feeling inclined to do any more any time soon though).
I did manage to remember to take a photo when I stopped stitching last night, so here it is:
The bottom half of both legs on the M are done, the top of the right leg is padded. About half of the rest is outlined - and in this photo you can actually see my yellow guide stitches, and the long tails where I'm pulling them out as I go. There is a little bit of unevenness on some of the edges, but I'm planning to outline everything with couched gold anyway.
I love the way the satin stitch looks, which I guess is probably the redeeming feature of the stitch. I'll try and get a daylight photo in the weekend (here's hoping for some not-too-gloomy weather).