The problem with TFE and other dry lubricants is that they afford no corrosion protection.

After all the rust has been removed, the surface of the metal will be finely pitted and 'active' - all set to rust again unless a sealing coat that will get into the microscopic pits is applied.

WD-40 was originally developed (or so the story goes) for preventing rust on polished steel [not stainless steel] rocket nose-cones. The accronym stands for 'water displacing formula #40'. It wasn't designed to be a lubricant but to be a penetrating drying oil. After WD-40 dries it gets very gummy and is a very poor lubricant.

Machinery, like bicycles, will have been coated with a fine film of penetrating oil at the factory. If this protective oil is removed then TFE lube is not the right thing to use.

In retroscpect, a light wipe with WD40 for corrosion inhibition, followed by a light oiling with SAE30 may be the best solution.

Old machinery, such as this camera, often had a clear varnish applied to the steel to keep it from corroding. With time the varnish develops cracks and moisture gets under the varnish and corrodes the metal.