I've absolutely no problem with the Beavers having "working-class accents" — they are presented in the book as salt-of-the-earth types, and I'm pretty sure most adaptations have given them accents that suggest those kinds of characters. The audio book of LWW (read by Michael York) gives them Yorkshire accents!

I do still totally object, though, to them calling Aslan the "top geezer" — or "bloke", or "guy", or even some more modern colloquialism like "head honcho". If you read their dialogue in the book, both Mr and Mrs Beaver speak of Aslan with the utmost respect and honour, as you would expect for true Narnians. They don't use flowery formal language, but they never say anything about him that comes across as jokey or slang-laden or irreverent in any way. And that's vital, as I know some of us here have been saying in recent discussions about the Pevensies' reactions to hearing Aslan's name for the first time. We need to have this sense that Aslan is someone who evokes complete and utter awe. Otherwise the heart of the whole Narnia saga is gone.

That, in the end, was the ultimate reason why I couldn't, and still cannot, accept the Walden movie of LWW as a faithful adaptation. They clearly, patently, just did not "get" Aslan. And that brings everything else crashing down.