A oldie from 1950 that sat in my Netflix queue for a long time. Very British, very dark comedy.
Alec Guinness plays George Bird, a lonely loser who sells farm machinery. A spot of indigestion takes him to the doctor, who x-rays him and diagnoses Lampington's Disease, invariably fatal. Although he feels fine, the doc assures him that's the way with Lampington's: you feel just fine until you slip into irreversible coma and death.
George decides to cash out his life insurance and savings and live it up at a posh hotel. There he becomes acquainted with both the hotel staff and its upperclass guests. To George's consternation, his life actually starts getting interesting, with professional and romantic opportunities. But—oh oh, omens—a mirror breaks, the ace of spades keeps turning up,…I may have missed a black cat or two.
I did mention this was a dark comedy, right?
The credits show "David McCallum" in a bit part as a violinist. Could it have been Ilya Kuryakin/Ducky Mallard in a movie so old? A quick trip to IMDB says: nope, that was David McCallum, Senior in the role. And he was more than qualified to play the violinist: back in the day, among other things, he was Concertmaster violinist for the Royal Philharmonic Orchestra.