Fixing the Printhead not inserting squarely

I noticed that identical printers would print differently, one printing a rough surface in spots and the other not. I traced it down to the printhead not being inserted absolutely square to the metal plate. On my printheads I changed the bottom plastic to be completely round against the printhead so that when the printhead was inserted it was square before I tightened the screw. It makes a difference for the better. Attached is the STL for the bottom plastic with that modification.