The local dealer gave me their input too, of course with a quote, but even they sounded nervous doing it. All their horror stories like you mentioned "crane operator" where pitting on barrel was drastic. But for sure they mentioned dropping the whole swivel down underneath. I'm going with a quick fix on this one. I'm capping the 4 air lines on the swivel and pulling them on the outside with slinky coil D.O.T. air lines. They just can't turn the crane more than like 270deg. The only line I couldn't find was where the 1/4" air-pressure gauge line goes to on the underside of the swivel. I was thinking that it's tied to the pressure line in the swivel, but not sure yet. I was going to put a tee for it on the outside, and therefore use 4 lines instead of 5. It's the main air supply, parking brake, forward service brake and rear service brake all on 3/8 tube, + (pressure gauge 1/4 line).