Gee,, if I get into the dungeon,, dig into a box or twenty,, and happen to find a set of the Birdshead factory, poly ivory grips,, would I win a prize?
Ruger will send you small parts like the grip spacer free by calling this #(336) 949-5200. Thegrips spacer is the same as the width of the grip frame; 1/2" om this model.
I have not found a problem with the faux ivory grips being too fragile. But if the locating hole at the bottom is a bit too tight, and/or the grips are too snug at the top, I believe that causes them them to chip out at the bottom. Relieve the top a bit or enlarge the hole slightly until they don't have to be pressed on the grip frame.
Altamont makes the faux ivory grips for Ruger and they sell the bonded birdehead w/o ruger medallions for $28 here: https://www.altamontco.com/pistol-grips/ruger/vaquerobirdshead/