Downton Abbey meets Dexter?

Kind Hearts and Coronets was filmed in 1949, is absolutely brilliant black comedy, and has never been remade. If you think of it as a sort of dark comedy Downton Abbey / Dexter crossover you'd think it would be a natural, especially as a pediod drama series, but they've never done it. Interestingly, the original novel on which it is based, Israel Rank by Roy Horniman, is out of UK copyright, so it would be possible to film that without any problems.

Please feel free to pass this idea on to anyone who can use it!