FIG. 1 is a first perspective view of the mounting platform of my new design;

FIG. 2 is a second perspective view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a top view thereof;

FIG. 5 is a side elevation view thereof, the other side elevation view being a mirror image thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a back view thereof.

Where included, broken lines showing environment or structure are for illustrative purposes only and form no part of the claimed design. The dot-dot-dot lines adjacent the shaded areas represent the boundaries of the claimed design, while the dash-dot-dot broken lines depict environmental subject matter only, and form no part of the claimed design.