DIY: Thread Spool box- you could just use an old shoe box and then cut out a rectangle that fit the bottom. Put your desired amount of nails into it, and glue the rectangle with nail's head on the bottom down. Then paint the box.
Cut legs A & rails B, C to size. Cut hand hole & mortises for hinges in back rail. Cut half lap joints in legs & rails. Lay assembly on bench & clamp swing-leg assemblies on top in open position. Make sure top edges & outside faces of swing-leg rails