Shoe goo does work great if that's your only option. I don't have an Xray so can't help there but I have shoe gooed a few servos in my time. Just apply it, position the servo and then I clamp it down with a big C clamp to hold it in place while it sets. Just firm enough pressure to hold it in place without squeezing everything out.
And if that's what you have to do, it's worth it. That's one bad mother of a servo.