I got a response from a couple of Jim’s High School Reunion committee. They are happy to have me attend - as long as I get Jim’s permission in writing. They’ve also asked for contact information for Jim.
I’ve sent them the details of Jim’s press officer in the UK - I think they want to invite him to the reunion. I’ve written back and told them that Jim will be too busy to assent to my attending - but if they tell Jim I’m coming, they can bar me if he has any objections. I’m relying on inertia and poor communications, an old editor’s trick which has generally worked well for me in the past.