“My problem with the vintage Gibson bridges is that Gibson’s fretboard radius will measure anywhere from a tight 9" to being as flat as 14", with 9" and 10" being as common as 12",” says Rowen. “Yet the Tune-O-Matic, as it is designed and produced, is too flat to be easily fitted for the more-curved radii.”
The Pigtail APR-1s provide a true radius that matches the fretboard, eliminating the need to file deep string slots in the bridge saddles to reach the desired radius. Also—and this is very important to me—the APR-1 saddles are un-notched. This means I can do with them as I please.
“I advise against removing the saddles from a TOM-style bridge,” says Rowen, “because each time you remove and replace a saddle, you loosen the original tight fit.”
Unfortunately, the G and low-E strings often intonate sharp, which necessitates removing those saddles in order to reverse them—with the sharp edge of the saddle facing the tailpiece—to achieve correct intonation. In these cases, here is how Rowen goes about switching saddles.