I don't know about JandC, but I was of the impression that EFKE is a linear descendant of ADOX. EFKE KB-25 was earlier called KB-14, and is the same as ADOX KB-25 - within tolerances. It never went away, it just got renamed.

NOTE: The reason for the change from 14 to 25 is a change in naming from the DIN system to the current ISO. The film has always been named after its sensitivity. Same with KB-17/KB-50, and KB-21/KB-100 (don't know why they pulled 1/3 stop off the 100, though...)