let screw_holes = column center {
[12] R<7.5>(h)
[11] R<7.5>(h)
[12] R<7.5>(h)
[11] R<7.5>(h)
[12] R<7.5>(h)
};
# To keep things neat, we define the internal geometry in
# a variable (screw_holes) and reference it in wrap().
wrap ($screw_holes) with {
top-0.5 => C<2>,
top+0.5 => C<2>,
bottom-0.5 => C<2>,
bottom+0.5 => C<2>,
bottom+0.417 => R<3>(smiley),
}