Use the layout in image 1 (below) as a guide for marking and cutting the body to shape. To mark the rounded end of the body, use either a beam compass or a do-it-yourself compass.
To make your own compass, grab a piece of scrap wood, paint stirrer, or a thin craft board. Cut it roughly 12 inches long. Mark a center line along the length of the board. Drive a 4d nail on a spot on the line near the end of the board (image 2). From the center of the nail, mark a line that matches the length of the radius you need to make - for this project it's 5-7/8". Drill a hole on that mark large enough for a pencil point to fit through the board.
Drive the 4d nail into your radius distance mark on your project piece and draw the radius (image 3). Use a jigsaw to cut off the excess (image 4).