Peel from 4 lemons (removed in strips with vegetable peeler)
1/3 cup superfine sugar
2 cups fresh raspberries, divided
3 cups Plymouth Sloe Gin
2 cups fresh lemon juice
1 1/2 cups Coruba dark Jamaican rum
6 cups ice cubes
1 ice block
2 cups chilled brut Champagne
Place lemon peel strips in large bowl. Add sugar and mash with muddler or wooden spoon to infuse sugar with lemon. Add 1 1/4 cups raspberries and mash to blend. Pour in sloe gin, lemon juice, and rum. Add ice cubes; stir to blend.
Refrigerate punch 20 minutes.
Place ice block in punch bowl. Strain punch over ice block into bowl. Add Champagne; stir to blend. Garnish punch with lemon slices and remaining 3/4 cup raspberries.
Ladle into punch cups.