I was talking to Fakir Musafar some months ago, and he told me that the now retired BR Creations corsetieres were the only people licensed to make corsets using his patterning techniques.
Now what's so special about his patterns?
They were designed to conform around the hip bones and ribs, yet pull in the waist as tightly as possible to create that hourglass shape.
While this goal may seem obvious to anybody who's lusted after a corseted body, it's really difficult to do.
After buying my first 4 corsets from BR Creations, I've bought a custom corset off eBay and another from DeMask, and neither has given me that wasp waist quite like the BR Creations.
He did also say that there are some active corsetieres who do use his techniques without paying him royalties, although he won't pursue an infringement case against them.
If I ever get the chance again, I'll have to ask who they might be.