The Count of Maurepas (Wikipedia), Secretary of State of the Navy in 1723-1749, used the code below (DE=337). It is rearranged from the reconstruction provided by Alexandre Pillon, a collector of ciphers who own two letters dated 17 October 1733 from Maurepas.
The recipient is a person who provided information in the Spanish court. ("m. le Cte de Rottembourg"(a French diplomat sent to Spain (Histoire locale de Masevaux)) and "m. de Patiño (José Patiño, de facto prime minister of Spain (Wikipedia) or his brother Baltasar in Paris (Wikipedia)) are mentioned in clear.)
The size of the code is 500. This has a two-dimensional array of numbers running horizontally and syllable/words alphabetically ordered vertically. Such a structure is similar to the one used by the Cardinal of Rohan in 1721 (another article) as well as some used in the reign of Louis XIV (items (3)(4)(8B) in another article and Le Tellier-Colbert Cipher 2 in yet another).
Later in the century, in 1782, the Secretary of State of the Navy (the Marquis of Castries) used real two-part code with random assignment of numbers in correspondence with Barbé-Marbois (see another article) and with Guillaume de Bellecombe, governor of Saint Domingue (see Pierrot et al. (2025) quoted in my blogpost).