The 'Churchill was really Norman Shelley' myth is vigorously contested in the wiki entry on N Shelley, and well debunked in

http://www.winstonchurchill.org/learn/myths/myths/an-actor-read-his-speeches

It was apparently the result of a confusion: Shelley had recorded one of WSC's speeches for the US market, with his approval and even to his amusement. The canard that they were all delivered by him was apparently the invention of David Sinclair, the notorious Holocaust-denier & all-round nasty, together with the other canard that Churchill was an excessive drinker, which he wasn't,

Sorry to drift so far from Toytown; but one of that programme's actors [who apparently was himself instrumental in confirming & spreading the 'speeches' lie] was much involved in all this so I think it has some relevance.

He was Winnie-the-Pooh on Children's Hour also, BTW!