Don't know whether this can help u.
From my v v v vague memory, the split between inbd/outbd elevators in the 74 is subject of a v early SB. Maybe the with aerodynamic loading on the hori fin in flight, its curvature may change/bend and with the split a straight line may restore.
For the fwd/aft freight holds aircon, are u saying the B747-400F ?
Any ideas from fellow engineers ?
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Not much of an engineer