I did a design of those. Made some prototypes but it still would chip paint off. If you got the insert soft enough not to do damage the inserts were weak enough they did not last. If you do have to do adjustments use an old hankerchief over the bolt and a 6 point socket/wrench. If you have access to an airbrush do touch ups with that.

1959 Bugeye Sprite
1967 Charger Black L code
1967 Coronet R/T Convert Green 440 auto bought from original owner
1968 Charger R/T Bronze 440 4 spd console AM/FM
1969 Super Bee WM21H B5 A40 D21 N96
1969 Barracuda Formula S 340 Convert pilot car
1969 Hemi Road Runner RM23J D32 Omaha orange 4.10 Dana N96 N85
1970 Super Bee WM23N FE5 V1X 3.91 axle package, N96
1970 Road Runner RM21N B3 V1X D13
1971 MG Midget
1971 Road Runner RM23H GW3, A57
1972 Road Runner RM23P FY1, D21