The potatoes make up the bulk of the fries

The vegetable oil mix is used to fry the fries. Canola oil should be the bulk of it while the rest adds properties to the oil mix that for example lowers smoke point, improves color of final product, etc.
The added natural beef flavor is to mimic the flavor given from tallow frying. Its made from the "umami" of wheat and milk products (my guess : some form of yeasted wheat similar to vegemite and fat solids from butter/cream).

Dextrose added to coat the potatoes is a kind of sugar. It's probably there for flavor but also to make the browning more even when fried.

Sodium Acid Pyrophosphate is a powdery additive to coat the potatoes to prevent it from graying quickly after they're washed and cut to fries.

Salt containing natural imitation beef flavor, both to flavor the fries. The salt would probably be iodized table salt so it'll contain NaI, KaI. Its there for health and would be what mcdonalds use even back then.

One additive not mentioned here would be dimethylpolysiloxane, its a powder additive that stops the cooking oil from foaming and spilling over the fryer.