Well.. there is always the old Adage keep your friends close and your enimes closer. And I'm not suggesting doing anything to him persay, so much as...well being clever in the way we keep an eye on him.

He's an intelligent and curious individual. Offer him a job that'll make use of his talents and let him go off and do his own thing at the same time. Something that'll keep him amused. He was willing to work for the Queen I'm sure mostly for the amusement that it afforded him.

If he's reformed, as you say, then try if not make friends but build some sort of bridge over to him to at least keep him in sight.

Am I making any sense? I don't know... thinking was never my strong suit, having relied mostly on my good looks and luck.