Very good. I think, though, that a large part of the taste and consistency of the lamb is the searing of the outer layer of the leg before cooking. I might suggest a good 20-30 minute sear before smoking it. It seals in the juices. I mean - it REALLY seals in the juices.
Suggest that you try the oven version first, then supplement with smoker. In any case, do not bother with poisonous toxic green mint jelly. Yurgh. You don’t need it with this approach.
I find that lamb, like a good steak, is so much better served medium rare. Smoking of lamb, I think, would allow it to cook too long and bring out a gamier taste than grilling or roasting would. JMHO.