Murder at the White Palace by Allison Montclair

This is another installment in the charming Sparks and Bainbridge series. Iris and Gwen decide to throw a big New Year's Eve party for the clients of their marriage bureau. Iris's gangster boyfriend Archie has just bought an old nightclub called The White Palace, which he offers as a venue.During the renovations before the party, a body (wearing a very distinctive signet ring) is discovered behind a wall. That body turns out to be related to the death of Archie's father, years earlier. Of course, Iris and Gwen get sucked into the investigation, putting their own lives at risk. It's  quite the page-turner.