b = 50;
  h = 75;
  d = 30;
  w = 5;
  
difference () {
  difference () {
    translate ([0,0,h/2]) cube ([b,d,h], center = true);
    translate ([0,-d/2,75]) rotate ([30,0,0]) cube ([b+1,d,h/2], center = true);
    translate ([0,d/2,75]) rotate ([-30,0,0]) cube ([b+1,d,h/2], center = true);
    translate ([-b/2+w/2,0,15]) rotate ([0,0,0]) cube ([10,d+5,h-15], center = true);
    translate ([-b/2,0,45]) rotate ([0,45,0]) cube ([10,d+5,10], center = true);
  }
  difference () {
    translate ([-5,0,h/2]) cube ([b+2,d-w,h-w], center = true);
    translate ([0,-d/2,h-w/2]) rotate ([30,0,0]) cube ([b+1,d,h/2], center = true);
    translate ([0,d/2,h-w/2]) rotate ([-30,0,0]) cube ([b+1,d,h/2], center = true);
  }
}
    translate ([-b/2+10.5,0,3]) rotate ([0,0,0]) cube ([5,d-2,3], center = true);