I have often enjoyed a leg of lamb (bone in) on the rotisserie too.
To date I have not tried it on my ECB. Here in Ontario we mostly get lamb from New Zealand (very flavorful) but also local raised which is much milder in taste (veal like) It tends to be expensive, so I usually wait for a sale.
I looked up some info for BBQing boneless leg of lamb and found that you want an internal of 130Âº at finish.
Flavoring with garlic, rosemary, salt & pepper.
The New Zealand web site has many recipes, which should be easy to adapt to smoking.
Here is their link .... http://www.nzlamb.ca/recipes/recipes...amb.php#herbed
Can't wait to see how you make out .......!