You might look at the end of the grub screw and soften the edges of the
ring that is denting the eccentric housing. Be somewhat prudent in the
amount of torque applied to these. The Burley we started with had threaded
bump outs in the BB shell in which the grub screws fit and a problem with
a loosening eccentric resulted in a bit of ovalizing of the BB shell as the
grub screw lifted the shell away from the eccentric. Maybe 30-40 thousandths
gap developed.