I did not think that 1969 S codes used a metal S tube. Thought that they were paper? Was it a Metuchen thing? Have only seen a couple of 1969 Dearborn cars with 390-4V.
Believe the air cleaners, S tubes and heat shields were pretty much all the same across all plants due to federal emission standards by 69.
It appears that what Ford shows is the reducer at the snorkel and the paper/tin foil tube but can't explain why the one example has what appears to be a 68 style or 428 steel style S tube. The later MPC shows that a number of 69 engines changed to paper/tin foil tube in Oct production but does not show that change for the 390 4V. Not sure if its correct or a mistake but the one example would likely have been built after Oct
The use of the paper tube may have somethign to do with the change in the heat shield design between 68 and 69