I have the same problems have been told a spinal fusion would probably not help my neck as I have stenosis too. Living with the same or similar pain as your Dad
Heat pads.
Oxynorm,
Buprenorphine plaster or Oxycontin.
Stretches, lifting any resistance, raking the lawn make it flare up , smoke weed and rest instead.
The best pillow and this did make a real difference for me was an ortheopedic pillow I bought on amazon.