Convince your Dad to get back on Celebrex. Seriously. I mean, what's the big deal? An increased risk of heart attack---even though the risk remains low---versus constant pain. I'll tell you what I'd pick at his age.
My dad is 59.
He lost his favorite brother a few years back to a massive heart attack, and heart disease runs in my family.
He hasn't mentioned it but I am sure that's his motivation for quitting both.
My mom has tried to convince him to stay on the Celebrex but he's quite stubborn, just like his son. ;)