After winning the Best Actor Oscar for 1969’s True Grit, John Wayne returned for a sequel with 1975’s Rooster Cogburn – which celebrates its 49th anniversary this week – alongside Katharine Hepburn. However, Duke had severe health issues going back to when he had a cancerous lung removed a decade prior.

Earlier in 1974, Wayne headed to London to shoot the cop movie Brannigan but had a severe bout of pneumonia and was diagnosed with heart problems before production began.

During…