The ornamental design for a surfacepattern for vehicleseat backrest, as shown and described.
FIG. 1 is a front perspective view of a surface pattern for vehicle seat
backrest showing our new design, it being understood that the broken lines
are for illustrative purposes only and form no part of the claimed design;
and,
FIG. 2 is an enlarged fragmentary front elevational view of the backrest
portion thereof.