There was at least one high-profile earlier case of f to m 'sex change' in the UK, an athlete who transitioned during the 1930s to a good deal of press coverage - heard a paper about this at a conference in the spring, and it appears that intersexuality issues may have been involved. Occurs to me that the person who gave the paper may also know about Sir Ewan... we are more or less in touch so I could ask them if you're interested.