Trim piece needed

...hmmm, the Mod 3 doesn't have this.

It looks pretty flat, so perhaps you could get a strip of thin aluminum sheeting from Home Depot and cut it to fit. Aluminum can be easily cut on a table saw; just use a cheap blade with 40 or more teeth (10" diam).
The beauty of Fiberglass (and wood) is that it can be repaired . Lay the piece on a flat surface covered with wax paper , build up the damaged areas with epoxy and fiberglass strips to the desired thickness, trim , sand , fill , and paint and your good to go

Good luck!