In a large pan combine the vinegar, wine, water and seasonings, bay leaves and mustard seeds pour this mixture over the meat. Add the sliced onions and garlic. Keep meat in the refrigerator, covered with marinade, for 1-3 days, turning occasionally. If you can weight down the meat in the marinade to submerge the meat completly with large cans, or some clean bricks. Remove meat from marinade, wipe dry with paper towels and in a deep large pot add the oil over high heat sear the meat till brown on all sides, sprinkling with 1 tablespoon flour. Strain and add marinade, cover, lower heat to a simmer and cook gently for 4-5 hours, until fork-tender. Add beef stock if needed to keep the beef submerged in the cooking liquid. Remove meat and keep in warm place. Pour off the stock. In the same pot, melt the butter, add the remaining flour and the sugar, stirring until smooth and browned about 7 minutes. Slowly add the stock, stirring with a whisk, cooking until smooth and thickened. Add the crushed gingersnaps, and cook until dissolved. Replace meat in the sauce and cook 1/2 hour longer on low simmer. Meanwhile, cook buttered noodles to serve with the sauerbraten. When the beef is done place on cutting board, strain the gravy to remove any lumps. Slice the beef across the grain, serve on plates with the sauce and noodles. Garnish with some chopped parsley. This dish tastes better the second day.