If one had measles in the 1960s is it safe to assume that immunity still holds or show precautions be taken, and if so, what?

Answer 1

Getting measles gives you lifelong immunity. Since other infections also cause fever and a rash, you would need a special blood test to confirm you are immune if measles wasn't confirmed by lab tests back when you had it.

 

For more information on measles, the CDC measles chapter in their Pink Book (the go to guide for healthcare workers looking for information about "Epidemiology and Prevention of Vaccine-Preventable Diseases", its real title) is a great authoritative resource. https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/meas.pdf