Well, the twin engine bomber like Beaufort has A LOT of rivets. That means careful measuring, drawing measured lines with a pencil then driving the riveting wheel across all the lines and finally sanding it all down under water. If rivets still not clean, it may help to use Mr. Cement S glue and wipe the lines lightly with the brush moisten with the glue (not soaked just moisten or else you loose your hard earned rivets). Mistakes can be repaired with black CA glue.