I have to say I'm really impressed with this piece for the vast majority of this images it looks like you cheated and used Photoshop. It's that good! I do have some minor critiques, but it's over all its amazing! firstly there's 3 it could just be me but the impression I get from looking at his face is that he's lost his dentures. It could be the I'm just looking at this wrong, but he just seems too old here. the only other critique I can find are that 10's face seems a little off, as if the right side of his face were too far extended (though I'm willing to concede that I remember a similar looking Publicity Photo).
I'm speechless. Honest to god. I've been following you for a while now but this.. definitely one of your BEST PIECES (and I'm not saying that just because I love doctor who) it's scarily difficult to put multiple faces in 1 drawing, espeiclly when each one has their own quirks. and you just managed to capture them all so perfectly! Job MORE then WELL done