I have had an email exchange with someone who knew Mr Powell very well. He wishes to remain anonymous but has said I can pass on the following for your info:
I have been interested in the discussion on Godfrey Powell, who I knew very well. I never knew anyone refer to him as Geoff, he was always known as Goff (spelling?). A delightful person, he was a JP in Newport and WM of Albert Edward Masonic Lodge, in 1974, also in Newport, I lost touch with Goff when we returned to our native Lancashire. He was a good servant to the Monmouthshire referees, and I believe he served in every office as well as giving unstinting support to young referees.
It would therefore appear he was known as Goff as opposed to Geoff. I expect somewhere someone wrote it as Geoff, thinking Goff was a misspelling & that carried on through.