Prick the potatoes with a fork. Wrap each potato separately in aluminum foil and bake for one hour.
Let the potatoes cool 15 minutes then halve, lengthwise. Remove and set aside part of the flesh, being sure to leave 0.75 cm (1/4 in) all around. Transfer the skins, cut-side down, to a baking sheet fitted with a grill rack. Roast in the centre of the oven for 15 minutes.
In a small bowl, combine the bread crumbs and the melted butter.
In another bowl, gently combine the crabmeat with the remaining ingredients, ensuring some large pieces of crabmeat remain for texture.
Remove the potato skins from the oven, fill with the crab mixture, and sprinkle with the bread crumbs. Return potato skins to the same baking sheet and bake another 10 minutes. Serve immediately.