The Lanvin Murders was my S in my list, and is first in the Vintage Clothing Mysteries
It follows Joanna, the owner of an independent vintage clothing store. She is doing her best to eke out an existence, and has a few regular customers and sellers that she builds a relationship up with. One of these characters sells Joanna an authentic Lanvin coat, and ends up dead in the store after asking for it back. Seeing the police decide that it's not a suspicious death, Joanna takes it upon herself to find out about her customer's friends and family, to find out why her friend was murdered.
The blurb says:
All Portland vintage clothing store owner Joanna Hayworth wants to do is turn her back on the modern world and retreat into a carefully curated life of satin cocktail gowns, icy martinis, and old movies.
But when Joanna finds a key in a 1930s Lanvin coat cast off by an ex-showgirl, everything changes. The elderly woman turns up dead, and Joanna is pulled into a long-ago drama of back room deals, blackmail, and lost love. She must find a very real—and present day—killer before she becomes his next victim.
This was an enjoyable read. There were a few absurdities (but I don't know the life of a show-girl, so maybe they are realistic), and there were some characters that I would have wanted to find out more about and be investigated earlier, but overall that didn't detract from the story too much. As far as amateur sleuthing goes, this was interesting and at times you felt compassion and other times you were on the edge of your seat. An easy summer read.