FIG. 1 is a perspective view of a first embodiment of a shim for a rail insulator showing my new design;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a front elevational view thereof;
FIG. 5 is a right side elevational view thereof, with the left side elevational view being a mirror image thereof;
FIG. 6 is a rear elevational view thereof;
FIG. 7 is a perspective view of a second embodiment of a shim for a rail insulator showing my new design;
FIG. 8 is a top plan view thereof;
FIG. 9 is a bottom plan view thereof;
FIG. 10 is a front elevational view thereof;
FIG. 11 is a right side elevational view thereof, with the left side elevational view being a mirror image thereof;
FIG. 12 is a rear elevational view thereof;
FIG. 13 is a perspective view of a third embodiment of a shim for a rail insulator showing my new design;
FIG. 14 is a top plan view thereof;
FIG. 15 is a bottom plan view thereof;
FIG. 16 is a front elevational view thereof;
FIG. 17 is a right side elevational view thereof, with the left side elevational view being a mirror image thereof;
FIG. 18 is a rear elevational view thereof;
FIG. 19 is a perspective view of a fourth embodiment of a shim for a rail insulator showing my new design;
FIG. 20 is a top plan view thereof;
FIG. 21 is a bottom plan view thereof;
FIG. 22 is a front elevational view thereof;
FIG. 23 is a right side elevational view thereof, with the left side elevational view being a mirror image thereof; and,
FIG. 24 is a rear elevational view thereof.
The broken lines in the drawings illustrate portions of a shim for a rail insulator that form no part of the claimed design.