Sorry for the terrible pic.... camera phone or wait until I get in the darkroom next.... so camera phone.

Result:
-From the perfectionist bbqer point of view, I unfortunately had to cook it a lot faster than I would have liked. Consequentially, it didn't cook as evenly as I would have liked, leaving some parts not quite ready to pull and the bone still firmly attached.
-From my mouth's point of view....my god it was good! Despite the slightly uneven cooking, it was moist, tender, with a sweet flavour (no sugar needed in the rub for this!) and that unmistakable richness of lamb. Smoke was hickory, which did it a marvellous justice, though if I had more time to cook it I would have gone with cherry.
-The pieces which did not pull were by no means tough, in fact I was pleased in the end that I had some chunks, they had little bite to them, whilst being incredibly moist and tender.
-Rub was paprika and tomato with garlic, onion, a little cumin (not much), salt, pepper, cayenne.
-Foiling sauce was beef stock from the weekend's pot roast brisket with cyder vinegar and a little of the rub mixed in.
Conclusion:
A wonderful way to cook a piece of lamb shoulder, for sure, but, and this is not like me to say, I think there are better ways to cook it (merguez sausage anyone?). The consistent opinion from the wife and kids was "pulled pork would have been better". Would have been £2 a kilo cheaper too. With that said, it was an interesting experiment and I may well try a leg at some point. We also have a decent amount of leftovers. I'm thinking Lancashire hotpot at the weekend....