Well, after some digging, I finally got hold of the guy that bought the moulds for the Shakespeare 720, 620 and I think 520 ribs, along with the www.ribs-by-shakespeare.co.uk
website from Francis.
He still has the moulds, in the UK, can still make them, but has let the website license lapse because of the climate.
Thanks to Paul Lemmer for the contact details :-)
Some Shakespeare moulds do appear to have gone to China, but not those that most of us would think of as the moulds of Shakespeare ribs.