Dialect Help Resource: https://www.dialectsarchive.com/france
D'Artagnan: Dar-tan-yawn.
Athos: AY-thos
Porthos: pour-thos
Aramis: air-a-miss
Monsieur de Tréville: Muh-sior de Tru-vee
Gascon: gas-kon
Meung (pg 12) pronunciation: Meung-sur-Loire Pronunciation
Rapier: ray-peer
Pistoles: pee-sto-les
Bonacieux: Bo-na-show
Cristal: Kris-tal
Richelieu: https://www.youtube.com/watch?v=iwdHYY_e_mU
Merde: mayrd
fleur-de-lis: flur-duh-LEES
Lille: leel
Enculé: on-coo-lay https://en.wiktionary.org/wiki/encul%C3%A9