$fn=100;

CubePoints = [
   [   0,   0,   0 ],  //0
   [   0, 272,   0 ],  //1
   [  50, 272,   0 ],  //2
   [  50,   0,   0 ],  //3
   [   0,   0,  35 ],  //4
   [   0, 272,  35 ],  //5
   [  37, 272,  35 ],  //6
   [  37,   0,  35 ]]; //7
CubeFaces = [
   [0,1,2,3],  // bottom
   [4,5,1,0],  // front
   [7,6,5,4],  // top
   [5,6,2,1],  // right
   [6,7,3,2],  // back
   [7,4,0,3]]; // left

difference(){
   cube([12,270,23]);
   translate([3,-1,10.9])cube([10,272,13]);
   hull(){rotate([0,180,0])translate([-53,-1,-11])polyhedron( CubePoints, CubeFaces );}
   rotate([0,90,0])translate([-11, 12,-1])cylinder(20, d=5);
   rotate([0,90,0])translate([-11,127,-1])cylinder(20, d=5);
   rotate([0,90,0])translate([-11,255,-1])cylinder(20, d=5);
//   cube([132, 10, 35]);
//   cube([129.4, 20, 19]);
}