Link to where you boguht them by chance? And how are you planning on putting set screws in them? Are the they thick enough to be threaded? Awesome find and creativity sir.
I don't have anything against parts made by STG, I have exhaust made by him. I choose to make my own covers because I want it to be polished aluminum to match the polished aluminum 8* trees.
Final cost $10 ($8 for 1" of aluminum tubing + $2 for 6 set screws).