(Split the topic to get us focused on Cougars only)
Since you have photo documentation I would just reproduce/copy what you found. It does not appear to be dealer done, or added to by a PO.
With that said it looks like that the worker applying the product to your car stood at/near the end of the trans and shot back wards with the wand rather than walking backwards while applying. This produced a coat that appears (just based on what I can see in the pictures) a much thinner coat at the rear than at the front.
To help the discussion here are a few 69 Dearborn Cougar examples where they were only coated in the tunnel. It appears that (though it could happen of the worker got off target) they didn't plan on doing the floors on these examples/model of Cougar
Hope this helps
Nice picture showing the angle the exhaust clamps were installed from. Worker just stood in the one spot while tightening
Sample to show the thickness and close up of the texture of this one example