I think he'd be quite good in the role, so long as he can rid himself of all traces of the Brummy twang.
If an actor is good enough at their job you should be able to believe in any portrayal.
In the seventies I saw Prunella Scales as Portia in the Merchant of Venice. It only took a moment to convince me that she was Portia, and wasn't about to start shouting 'Basil!'
