well, we have few threads about them so probably reading those will satisfy your thirst
this search should give you a few hits
Lelandais kept existing under the name Chedeville
"... In 1949, Charles Chedeville sold the Chedeville company to 'Lelandais', a contemporary company based in Paris, France, that produced good quality and popular mouthpieces. 'Lelandais' continued to make mouthpieces with a similar design as those made by Charles Chedeville through the early 1970's. Later another French company 'Glotin' purchased the remnants of the Charles Chedeville and 'Lelandais' companies. ..."