I am finishing a restoration of a 1971 Gibson EB3L. But I cannot figure out how to get the bridge to sit flat against the body. When the strings are up to pitch, the back of the bridge angles up, making the action terribly high. What's the secret to making this guy work? The bridge attached to two adjustable height posts. Two small allen set screws tighten the bridge to the posts and seem to be the only things that resist the upward pull of the strings on the back of the bridge. I attach a picture to ditinguish this bridge from other Gibson bridges. When I got the bass, it was in pieces, (and missing several of them), and I have no example to work from.