Use mirror to print the suitable piece
Generated with http://openjscad.org/

function main() {
return union(
cylinder({r: 1, h: 0.3}).translate([0,0,0]).scale([10,18,10])
.subtract(cylinder({r: 1.5, h: 0.3}).translate([0,0,0]).scale([1,1,10]))
.subtract(cube(20,20,2).translate([-10,10,0])),
cylinder({r: 1, h: 0.35}).translate([0,0,0.3]).scale([8,16,10])
.subtract(cylinder({r: 1, h: 0.35}).translate([0,0,0.3]).scale([5,12,10]))
.subtract(cube(20,20).translate([-10,1,0]))
.subtract(cube(15,15).translate([0,0,3]).rotateZ(222)),
cylinder({r: 2.2, h: 8}).translate([-16,-6,0]).scale([1,1,1])
.subtract(cube(4.5,4.5).rotateY(45).translate([-22.2,-8.3,8])),
cube(13,13).rotateZ(55).translate([-6.3,-13.8,0]).scale([1,1,0.23])
);
}