Start by rinsing the roast with cold water, and pat it dry with a paper towel. Then cut the skin off, but leave the layer of fat on the roast.
Make thin cuts through the layer of fat with a sharp knife, with a half inch in between. Rub the roast liberally with the allspice and pork rub, and let it rest in the fridge for a couple of hours.
Get your grill started, prepare it for indirect heat, 110° C / 225° F. Add a few chunks of cherry wood and smoke the meat for roughly 4 hours until the inner temperature hits 65° C/ 150° F. Remove from the grill and let it rest for 20-30 minutes covered in aluminum foil and a towel. Slice it up and serve!