1. In 10-inch skillet over medium heat, heat sausages and 1/4 cup water to boiling. Cover; simmer 5 minutes. Remove cover and continue cooking, turning sausages frequently, until water evaporates and sausages are well browned, about 20 minutes. Remove sausages to paper towels to drain. Finely chop sausages. In medium-sized bowl, combine chopped sausages with eggs, fresh bread crumbs, and diced pimento.
2. Meanwhile, in 1-quart saucepan over high heat, heat whole green beans, 1/4 teaspoon salt, and 1 inch water to boiling. Reduce heat to low; cover and simmer 5 to 10 minutes, until beans are fork-tender; drain.
3. Untie veal sirloin roast; place, fat side down, on work surface. To make veal evenly thick, with sharp knife held parallel to the cutting surface, cut off horizontal slices from thick parts of veal. Press the cut-off slices where needed along edges of veal roast to make a rectangle about 12" by 10". Then, if necessary, pound veal with dull edge of French knife or meat mallet to make about 1 inch thick throughout.
4. Spoon sausage mixture onto veal; place green beans, parallel to short side, here and there on sausage mixture. Starting at a narrow end, carefully roll veal, jelly-roll fashion; fasten with skewers. Place veal roast seam side down; wrap roast with bacon slices, overlapping bacon slices if necessary. With string, tie veal roast at intervals of about 2 inches.
5. Place stuffed veal roast on rack in open roasting pan. Insert meat thermometer into center of roast. Roast in 325°F. oven 2 hours or until meat is tender and meat thermometer reaches 170°F.
6. About 30 minutes before veal is done, prepare rice as label directs but add saffron threads to rice.
7. When roast is done, remove strings and skewers; place roast on warm platter. Remove rack from pan. Skim 3 tablespoons fat from drippings into 1 quart saucepan; skim off and discard any remaining fat. Stir pan juices until brown bits are loosened from pan; pour pan juices into 2-cup measure; add enough water to make 2 cups.
8. Into fat in saucepan, over medium heat, stir flour and 1/2 teaspoon salt until blended; gradually stir in meat-juice mixture; cook, stirring constantly, until thickened.
9. To serve, cut veal roast into thin slices; arrange veal roast and saffron rice on warm large platter. Garnish platter with watercress sprigs. Pass gravy with veal.