Street of the Five Moons by Elizabeth Peters

 A great example of why I love this series even though it's ... 40 years old? Good Lord. So self-referential (you would never meet the villain at the end) and wry. Vicky Bliss is a fantabulous character. A blonde with a body like a centerfold, a mind like a steel trap, and the wit to keep you reading.
This time, there are replicas of famous items that are being put out into the world, including one from her very own university. So Vicky's off to Rome to figure out what's going on. Her adventures are fun and fascinating. As is John Smythe, the Englishman she meets along the way. 
The mystery is fairly clued with the reader able to guess the villain(s?) fairly easily. And all of the characters are painted so vividly including secondary characters like Herr Schmidt, the Italian principessa, Bruno, the Italian count as well as his son, his mother, and his mistress. Even Caesar the dog.

Three and a half stars

Follows Borrower of the Night

Followed by Silhouette in Scarlet

This book came out in 1978

Borrowed as an ebook from the CloudLibrary

Opinions are my own