To be honest John, I have considerd the elevation of guns for future models and decided to restrict mine to traverse only ans that I do not have the same heart rending issues you have.
I learnt from your woes that after much effort in building turrets, you do not want to have to crack them open to fix the problem, or make really complex turrets with removable parts.
An option for fully mech turrets is to have the elevation servo and gear in a compartment underneath the turret that rotates with it, then everything is easy to access and possibly even sealable if the basket is tubular with a rubber or plastic cap?
I hope your Beauty is water borne soon, any chance if a short Youtue clip of her sailing?