Melies probably did use Lumiere Brothers stock and it was blue sensitive only; not even technically what we call orthochromatic today. For a short time in the history of film, the very first filmstock were dual purpose; both for negative and prints. You just used the same stock for different purposes and developed it to a higher contrast for the print.
I don't know that it is possible to fully understand just who was making motion picture filmstocks in that time frame, as all of Europe, especially Germany, was rife with small photochemical manufactures of glass plates, photographic paper and flexible base filmstocks.
Kodak held the majority lock on stocks in the USA and, with the help of the Patents Trust Company, maintained that hold for mainstream productions throughout the life of the Patents Trust Company, BUT independent distributor Charles Brualator (sp?) did supply many independent (aka "illegal") productions in the USA with Lumiere Brothers filmstock smuggled into the country.
