I bought a few compensated saddles to replace those on My GAD 212, D55 and one for My JF30-12, however, I'm replacing the bone with tusk. The tusk saddles and nuts are harder/denser material, and seem to last longer than bone. My ears tell me that tone is healthier with tusk as well.
On the JF30-12 and D55, I may have the bridge opened up for the thicker saddles, not sure yet, that may be in the not too distant future. For now, I'll leave the bone nuts in place, but should they deteriorate and crack, they'll also be replaced with tusk.
I bought the compensated saddles at a local guitar/music store, because I was able to select heights and lengths close to those I needed to replace.
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