The owner of the 1976 Gibson SG wanted to have it refretted, Sperzel tuners installed, and a roller bridge installed to replace the original harmonica bridge. When doing repairs or upgrades on vintage instruments I always look for ways of installing hardware doesn’t alter the guitar and if possible is easily reversible. The sperzel tuners were a good choice because the small hole for the locating pin is within the footprint of the original tuners. Switching back would be quick and easy and the modification would not be visible. The roller bridge, while it had the same post spacing required very different inserts. Installing the new inserts would mean plugging the original holes and redrilling. To avoid this I decided to make a pair of brass bushing that thread into the original inserts and are tapped to accept the new bridge posts.