Ebersole is too old for this role. Elvira is supposed to have died young (and the dead don't get older). I hope they can get Everett and, of course, Lansbury, but I'm kind of sorry to hear about Ebersole. Elvira is supposed to still be young and sexy (though dead).
The play is very long and the original Broadway production had cuts that were made by Coward but it's still long. But it's a brilliant script if it's done well.
I've never seen
High Spirits onstage but I agree with Smaxie about the score. Most of them are good enough songs but they don't seem to enrich the play.
best12bars, most of the original principals reunited to perform
Blithe Spirit on the radio for Theatre Guild on the Air. Only Peggy Wood was missing. She was supposed to do it but for some reason couldn't at the last minute (and I think she was replaced by her Broadway understudy).
This can be downloaded online at
http://www.archive.org/details/TheaterGuildontheAir Unfortunately, though many of the Theatre Guild on the Air broadcasts are terrific, the
Blithe Spirit is awful. Not only is the script greatly cut to fit into the hour time slot, but it's rewritten to a huge extent. I think less than half the lines are actually Coward's. And the cast sounds underrehearsed, with Natwick going up a number of times on her awful new lines. Very disappointing.
Still, that website has some terrific stuff. I especially recommend
The Importance of Being Earnest, The Great Adventure, The Glass Menagerie, and the
Hamlet. I haven't heard all of the ones on that site and I imagine others are good as well.
Natwick did play Madame Arcati on Hallmark Hall of Fame in the 1950s, with Coward, Bacall and Colbert as Charles, Elvira and Ruth. I haven't seen it but I'm told it's terrific. The Paley Center has it.