Is there a student of him in England, who could invite him?
Actually Endo Sensei has been to England before! He gave a wonderful weekend course in Birmingham in 2003. Cath Davies of the UKA organised this visit, and has had connections with Endo Sensei for a few years. Perhaps you could persuade her to ask him back?
Here's Cath's webpage:
Oh, and I'm looking forward to seeing Yamashima Sensei in Bath this Sunday - he is definitely well work seeing!