Soften gelatin in cold water. Heat tomato juice, add gelatin, and stir until dissolved. Add lemon juice and salt. Chill until partially set.
Combine remaining ingredients and fold into gelatin mixture.
Pour into 8 1/2 by 4 1/2 by 2 1/2 inch loaf pan or 1 1/2 quart mold. Chill until firm.
Garnish with slices of hard-poked egg, cucumber slices, tomato wedges, and watercress if desired.