The ornamental design for a long diamondshapedtrailingfender, as shown and described.
FIG. 1 is a front perspective view showing my new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a left side elevational view showing my new design, the right side being a mirror image;
FIG. 4 is a top side elevational view thereof;
FIG. 5 is a bottom side elevational view thereof;
FIG. 6 is a front elevational view thereof;
FIG. 7 is a rear elevational view thereof;
FIG. 8 is a front perspective view shown in relation to a mounting block. The mounting block is shown in broken lines and forms no part of the claimed design; and,
FIG. 9 is a back perspective view shown in relation to a wheel. The wheel is shown in broken lines and forms no part of the claimed design.