Using a combination of original standoffs and long bolts I think I’ll have enough to reach from the top shelf to either the base of the case. Or the bottom shelf, depending if I cut out a hole that fits around the power supply. Which will secure it and also lets me access the modular cables. To glue them together, I'm getting this Steel Reinforced Epoxy. It's Arriving Tuesday, I'm not going to rush this stage, I'll plan it out and let the epoxy have time to cure properly.