I recently purchased a Mustang Vintage Sport Solo Seat with backrest for my Motortrike VTX 1300R. It seems that the curvature/contour of the fiberglass shell behind the driver seat, just above the spot where the seat connection bolts are, is too high, and prevents the Mustang seat from fully dropping in to its proper spot. The bottom rear of the Mustang seat actually rests on the fiberglass shell. The OEM fit just fine. Anyone have this problem, and how did you resolve it? Thanks.