Combine 1 cup of the olive oil, the Worcestershire, red pepper flakes, onions, scallions and lemons in a large bowl or large zip-top bag. Add the chicken pieces and toss to coat. Marinate in the refrigerator for at least a few hours.
Prepare the coals on an outdoor grill to medium hot or heat a gas grill. If using coals, bank them to one side of the grill so that one side is hot and the other less so.
Remove the chicken and vegetables from the marinade and transfer to 2 baking sheets. Discard the marinade. Sprinkle the chicken pieces well with salt and pepper and then place the chicken, onions, scallions and lemons onto the grill. You may lose some scallions or lemons, but hopefully most won't fall through the grates!
Put the cover on the grill to increase the heat and cook the hell out of the chicken. The grill will smoke like crazy, but try to resist opening the lid for 7 minutes or so. Open the lid, flip the chicken and continue cooking, mostly covered, until the chicken is cooked through, about 35 minutes total. If the chicken, lemon and onions are getting too charred, reduce the heat or move them to a cooler part of the grill, flipping as needed. Remove from the grill and let rest for 5 to 10 minutes before serving.
Meanwhile, mix together the remaining 1/4 cup olive oil, the parsley, vinegar and anchovies, if using.
To serve, brush the bread with olive oil and grill on both sides. Divide the chicken, lemon, scallions and onions among serving plates. Place the tomato wedges alongside and drizzle with the vinaigrette. Serve with the grilled bread.