BigBox Slim Fume Hood Rails

Wanting to print those toxic plastics, but not wanting to breathe in those fumes... So, I designed two versions of a fume hood for my BigBox... I printed my first version before slimming it down for Fume 2.0, which wastes less plastic, since no support material is needed to print the files (but it does lack the sewer lid plugs from my first version)...

Anywho, these rails were designed to cover up the holes on top and uses the existing bolts already there to hold them in place and the rails a