$fn=200;

rotate([180,0,0])union() {
    difference () {
        cube ([168,105,23]);
        translate([-0.5,1.5,-0.5])cube ([148.5,102,24]);
        translate([150,25,-0.5])cube ([20,55,20.5]);

        translate([28.5,105.5,5.5])rotate([90,0,0])cylinder(h=106,d=3);
        translate([70,105.5,5.5])rotate([90,0,0])cylinder(h=106,d=3);
        translate([130,105.5,5.5])rotate([90,0,0])cylinder(h=106,d=3);
    }
    translate([163,24.5,15])cube ([5,56,5.5]);
    translate([165.5,80,15])rotate([90,0,0])cylinder(h=56,d=5);
}