Butterflied leg of lamb

[cameraman]

I picked one up at Costco yesterday. I've cut all the fat and silverskin off and rubbed i with an olive oil / rosemary / garlic / s&P marinade and it's vacusucked and sitting in the fridge. I think I'm going to tie it back into a roast and cook it offset on the kettle. It's a 5 pounder. I'm going to shoot for about 250 or 275 and look to hit around 140-145 finished after a 30 min. cooler rest. Can you give me a clue how long I should plan for on the grill? Should I do a reverse sear? Am I making a mistake not using the WSM? Any thoughts or suggestions are appreciated. Mmmm lamb. TIA

 

[Pyle's BBQ]

I did a boneless leg from Sam's at the Bash last night. I peeled the netting back just enough to open it up and seasoned this inside and folded it back up. I pull the netting back over it and seasoned the outside. I banked coals on one side of the Weber, put the leg in a basket and put the spit through it. I think it was on the spit about 2 hours. I pulled it a 145*F due to extra curricular activities. I did want to pull it at 135*F. Your idea of tying it up is spot on.