As we age, the chances of really developing something with serious consequences increases. Your father's age is a red flag all by itself. And the fact that he's developing new symptoms he hasn't had before is also important.
A visit with his primary care doctor is probably in order. If your father's symptoms are psychologic in nature, the results of sensory or motor tests will be negative (normal). A simple X-ray of the neck and spine can give the physician quite a bit of information to help sort out the symptoms.
If finances are a concern, there are a wide variety of tests that can be done by the doctor with your father in the office that don't cost extra. It's probably time to take a first-look. The fact that you're concerned tips the scales in favor of an exam at this time.