Marinate roast in next 7 ingredients, covered in refrigerator for 18 to 24 hours. Turn meat occasionally.
When ready to cook, drain meat well, saving marinade liquid. Brown meat in bacon drippings in Dutch oven or deep skillet. Strain marinade; add liquid to meat and simmer approximately 3 hours, or until meat is tender. Remove meat and strain remaining liquid into a bowl. Blend flour and butter in pan and add strained liquid. Stir until smooth and slightly thickened. Add salt to taste. Place meat in gravy; heat for 5 minutes. Serve sliced meat on a hot platter, pouring gravy over the roast.