http://www.aussiehomebrewer.com/index.php?/topic/86008-Stalled-Old-Ale-help
It stopped dead at 60% attenuation. To be fair, on the 3rd night it dropped to 16-17*c and it didn't move since then.
Another week of 22-23*c, still no movement. So I've prep'd some kit yeast to see if I can get it down a little further in a FF test.
Largely my fault for selecting the wrong yeast, really. MJ recommend the British Ale yeast for an Old Ale, and really seem to recommend the Dark Ale yeast more for just Milds - where a 60% attenuation might work well.
Annoyed the temp dropped, though. As I'm now not sure if it's stopped because of that or if it normally stops ~60% attenuation.