Thank you so much everyone, I spent a very intense few hours with DS after work yesterday (left a little early), and he was really happy. Slept better (if still a bit unhappy) and of course we didn't have to go anywhere this morning so we just did loads of digging (mm, Bob has a lot to answer for) and tickling... He went down for his nap like a charm... obviously it was just a matter of time and I felt it was going to go on forever......
Anyway, thanks again, you're stars!