Who was the first person to perfect interchangeable flintlock parts for mass production?

Honoré Leblanc is recognized for his pioneering work in perfecting interchangeable flintlock parts, which significantly contributed to the concept of mass production in firearms. By standardizing components, he made it possible for parts to be easily replicated and replaced, which was revolutionary at the time. This innovation allowed for greater efficiency in manufacturing and repair, ultimately leading to the widespread availability and reliability of flintlock guns.

Other figures mentioned in the options had notable achievements in the firearms industry, but they are not primarily associated with the development of interchangeable parts for flintlocks. For example, Louis Flobert is known for creating the first commercially successful rimfire cartridge. Dr. Benjamin Robin contributed to the understanding of ballistics, while John Browning is celebrated for his designs of many modern firearms, but he worked in a later era with different technologies. Thus, Leblanc's contribution stands out in the context of the question.