Mounting Accesories to the Vacuum Table

I am wondering what the “inside” of the vacuum table looks like. Basically, on the Y+ end of the machine I was considering mounting the tool tightening fixture from the iso20 kit and maybe a fixture to hold the wrenches. But I don’t know where it is safe to drill through the table without piercing the vacuum envelope or recking the gasket. The solid model of the vacuum table (which is awesome, thanks for that) is solid on the inside so it didn’t answer my question.