Barbecue Butterflied Leg of Lamb

1 (6 pound) leg of lamb, boned
    trimmed and butterflied

Marinade:
1 cup catsup
1/4 cup Worcestershire
Few drops of Tabasco sauce
1 teaspoon chili powder
1 cup water
1/4 cup brown sugar, firmly packed
1 teaspoon celery salt
1 teaspoon salt

Combine sauce ingredients in a 2-quart pan. Bring to a simmer, but do not boil. Remove from heat and pour over lamb. Marinate overnight in refrigerator. Barbecue lamb 8 to 10 inches from hot coals for about 50 minutes, turning often and basting every 10 to 15 minutes. (DO NOT OVERCOOK. It should be crisp on the outside and pink inside.