Vintage Murder is the 5th of 32 Inspector Roderick Alleyn mystery novels by Ngaio Marsh. I pick these up whenever I see them used, which isn't often. I may have to start looking at the new book stores.
from the back of the book:
The leading lady of a theater company touring New Zealand was stunningly beautiful. No one -including her lover- understood why she married the company's pudgy producer. But did she rig a huge jeroboam of champagne to kill her husband during a cast party? Did her sweetheart? Or was another villain waiting in the wings? On a holiday down under, Inspector Roderick Alleyn must uncork this mystery and uncover a devious killer...
I've also read
#1 A Man Lay Dead
#10: Death of a Peer
The photo at the top of the post is from Macmillan.com, where you can pick up a paperback edition for $5.99.