Next time, try leaving the rind on until after smoking; it will harden up, then you can slip your knife under the edge of the skin and loosen it and peel it off much easier. The skin is pervious and will allow smoke flavor to penetrate it even though it's not brown underneath, you have more than adequate smoke flavor left in the belly after you remove the skin. We did 24 full slabs at a time in one smokehouse and would de-rind 18 - 20 of them after smoking; the slabs closest to the smokehouse walls would sometimes overcook a bit and we'd just slip the knife under the edge all the way around, then grab the rind with a pair of channellock pliers and pull the rind off if warm enough, lol! But, we never de-rind'd the belly before smoking, it would be way too floppy and hard to do, esp. with the soft skin. The rest of the smoked bellies we sold with the rind on; about 20% of people liked to chew on the rind (just like fresh sidepork (fresh belly), always sold that with the rind on, as well as salt pork (pickled belly)...).