FB-111A follow on ?

Ok, we have the FB-111A. But the serie aparently continued after that, until the FB-111H proposal of 1979.
Joe Baugher briefly detail the FB-111B, but we still lack
– FB-111C
– FB-111D
– FB-111E
– FB-111F
– FB-111G

This serie is INDEPENDANT from the F-111 (A/B etc.)

anybody has detail about these projects ?