QUOTE:
"There were a few RAF crew doing exchanges with the US, but they certainly were not allowed into Vietnam. Even transport crews were only allowed partway across the Pacific."
One RN crew - on exchange with VF-121 at Miramar - certainly delivered a USMC Phantom to Vietnam in the late sixties. They opened the refuelling probe when they arrived in Da Nang to reveal a Union Jack they'd wrapped round before leaving on the last leg of the journey. Just there for a couple of days. No combat.