If it has a black border it is a reversal film. If it has a clear border it is probably a print film.

Some of these old films can be restored by soaking in strong ferricyanide solution. I would test a small piece first before I tried this. I have done it and if it is the wrong type of film nothing bad happens. If it is the right kind, the cyans are restored.

Here is the 75 deg F process:

Soak in ferricyanide solution until restored, but not more than 10 minutes. (50 g/l Sodium or Potassium Ferricyanide)

Wash for 10 minutes in running water.

Stabilize in old style stabilizer with formalin. (Mix up Photo Flo 200 as directed and add 10 ml of 37% formalin).

PE