Essence Super Gem replacement woofer(s)

A friend of mine has some Essence Super Gems with a blown woofer.  Somewhere along the line the woofer was misplaced.  He wants to get a replacement pair if he cannot source another original to replace the misplaced woofer.  It is my understanding that Morel made the drivers for the Super Gems, if that is not correct could someone correct me?  If someone knows the specs for the Super Gem woofers that would also appreciated, such as sensitivity, etc.  If he needs to get a replacement pair, it is my understanding that Morel does not make the model used in the Super Gems so what current model Morel would be best suitable as a replacement woofer pair?  Any help would be very much appreciated.  Anybody ever rebuild the crossovers in the Super Gems?  Thanks much. 
The drivers were made by Morel but they were custom made for Essence. That's what Dale Pitcher, the man who was Essence, told me back in the 80's.