One of the remaining mysteries to me about the F-111B program was the presence of the four-segment flap wing (i.e. the F-111A wing) on F-111Bs #1 and 4. I didn't even notice it in the picture of #1 on the cover of my F-111B monograph until someone eventually pointed it out.
Note that the wings have the ferry tips so that the span is that of the F-111B.
This is the F-111B early five-segment flap wing.
Tim Lent pointed out that F-111B #4 also had a four-segment flap wing at one point.
(You can take my word for it - a lightened version of a high-resolution scan of a pretty good photograph shows that the fifth flap segment is not present.)
The reason for Tim's search for evidence of this wing on #4 was the desire to identify the third F-111B in this photo, the one with its back to the camera.
My speculation is that this set of wings was specifically instrumented for high-speed envelope expansion and the use of the ferry tips allowed it to be used by both General Dynamics on an F-111A and Grumman on an F-111B. In fact, #4 was used for flutter/envelope expansion in late 1966 and early 1967. After its crash, #1 was used for flutter/envelope expansion at Edwards in the fall of 1967, which is likely when the monograph cover picture was taken.