David,
I think we are on the same page, just talking about different chicken wire. You are referring to the wire for the intake grills below the roof, which did remain. What I referred to in my post was the chicken wire found on Phase II units between the two portholes, which I am not sure Southern ever had any (but Intermountain modeled). I have that book too, and also check southern.railfan.net for additional images as well.
It would be nice for 3rd Rail to make Southern F3s after the 1950s era rebuilds, but not sure if the market would generate 20 - 30 orders. Maybe he could look at making a standard Southern F3 Phase IV (F7 clone) and an F3 with the roof tanks as an AA pair. Would definitely be a one of a kind set!