Helen Hayes as Miss Marple in Murder with Mirrors

I have been away and watched some current day television. It was rubbish, by and large, but gave me some ideas for posts here. I watched some Murder She Wrote and remembered how I got myself in trouble some time ago by asking if Angela Lansbury strikes Americans as a convincing American. I was hoping for a yes or no answer and didn't get one! So I thought I'd relive it by writing about an American playing Miss Marple.
...who of course isn't a convincing English person to a native speaker, but this film does a good job overall of portraying a cast of mixed nationality as British, while having a good go at dealing with our ridiculously complicated social stratification, and the film ends up very watchable. I would be interested in how they sound to US viewers.
In general I shouldn't like this film, because it is a festival of big names, in addition to Helen Hayes we have Bette Davis and Leo McKern. They are such good actors that their presence isn't distracting. I see that both Davis and Hayes were over 80 when they made this and Davis had been terribly ill in the preceding year. I hope I can take on new things at their age!
I have seen all four of the adaptations of this book (Murder Ahoy was based on it, but Christie wasn't impressed) and like this one best. IMHO the premise of this Christie is rather dissatisfying - the fact it takes place in a house running with delinquents muddies the water too much, but I feel this adaptation feels more like a conventional country house murder, and Miss Marple rightly spends the majority of the time investigating the relationships of the people who aren't delinquents. This is exactly the sort of investigation Marple excels at.
There is one part where it goes slightly wrong, where Miss Marple talks to the American character, despite being American herself. I like Helen Hayes a lot as Miss Marple. I like the way the little old lady act is portrayed as just that, in fact I think she is the perfect compromise between fluffiness and incisiveness of Marple.
My absolute favourite bit is where the police officer, who had been warned by a colleague, tells Miss Marple to stop pretending to be a doddery little old lady!
I don't really have any criticisms, unusually for me. I just wish Hayes was better known for playing Marple here. Her portrayals of Miss Marple are of course available in region 1 DVDs and in German region 2 releases. I have no idea what language the latter are in so buy at your own risk!