Regarding bridge pins and tone, all due respect, but I fail to see how any vibration of the strings in a healthy guitar can occur aft of the saddle or north or the nut. A guitar is no different from a violin or cello in that respect...think of the pins of a violin affecting tone...If you do have vibration or resonance directly behind the saddle on a guitar, there's a problem with the guitar. All sound/tone is measurable vibration....do the pins change tone because they make the top resonate differently even though they are sunk in the mass of the bridge? Do they add their own special individual tiny tonal ring? Either case would be a hard one for me to buy. Whether the pins are made of fossilized walrus ivory or hand-machined unobtanium, I don't think there are any physics to substantiate any real change regarding bridge pins in what is basically a mathematical length and frequency of vibration.
A fellow on Craig's is selling Keyser capos with a strip of "fossilzed ivory" glued on to the fret-touching part ($90 if you're interested), to go along with one's fossilized ivory bridge pins. He claims a tremendous difference in sound, evidently disregarding the fact that most of the time strings are fretted with flesh. Seems like the "ivory" would be hell on strings and rosewood fretboards, too.
I sure do like the look of fancy pins, though, put a set of pearloid black-eye pins from STEWMAC on my D 40 and they sure are purty.
Wontox