This family ( Normal & Italic in both variants : plain and outlined, so 4 files in the folder ) was created inspired from an engraved plate from the Diderot & Dalembert's Encyclopedia (publication beginning in 1751), illustrating the chapter devoted to the letters engraving technics. The plate bears two engravers names : "Aubin" (may be one of the four St Aubin brothers ?) and "Benard" ( which name is present bellow all plates of the Encyclopedia printed in Geneva ). It seems to be a transitional type, but different from Fournier ("1786 GLC Fournier") or Grandjean. Small caps are included in all styles.

https://creativemarket.com/GLC/1113488-1751-GLC-Copperplate-OTF