I removed the plastic (tusq) inlay in my Cort Earth, and sculpted the same shape out of the bone blank. I cut it with a metal saw, and sanded it with 60 and 120 sandpaper.
I made the top curve with the 60 sandpaper, and shaped the bevels with small files. Then I sanded again with 120 to make it smooth but not shiny, because my guitar's finish is matte, not shiny.
I left the same old strings but when I tuned them, they sounded like they were not that worn out, there is much more brightness, more medium and medium-high frequencies. What is great for me is I play fingerpicking with the flesh of my fingers, not the nails, and it made me lose some treble.
Well, the treble is back because bone does not dampen sound like plastic does. There's more power, too. With Ultex picks the volume and brightness are very strong. I used 0.60mm almost all the time, but with the extra treble, I need to play with a 0.73mm or the sound is kinda brittle.
I'm glad I finally made the change because my affordable dreadnought pours out much more harmonics, now.