Those would look really sharp on your trike.
The trim is most likely plastic with 3M trim tape for attachment. You can compare the front to rear radius of your fenders to a Tri Glide. They are probably pretty close, and a little time in the sun to soften up the plastic will let you gently bend them to the exact curve and attach them to your fenders. Just plan ahead, measure 3 times, mark accurately and stick them on carefully.