I have heard that Disney has changed their policy on unused days on older tickets. It used to be that any days on older tickets could be exchanged at no charge for a newer admission ticket to the parks. I have 1 3-Day Worldpassport ticket from 1987 ($78) with one day remaining and 2 4-Day All Three Parks 4 Day Passport from 1989 ($111) with 2 days remaining. Will they still swap those unused days for full admission for a day? They did the last time I used this type of paper ticket. We are planning a trip in June and I am working on tickets now.
Unless they have changed their policy very recently, yes, they will honour them. We visited Disney World in November 2016. We had 2 4-Day All Parks Passports from 1992. We had two days remaining on each of them. We bought them because they guaranteed no expiry and it was barely more expensive than buying two single day tickets at the time. Little did we know it would be so long before we would return to use them again!
We simply went to Guest Services and they took the tickets and issued us with the new electronic cards using a fingerprint for entry. They even advised us that we did not have to use both days on the same visit. Since the original tickets had no expiry date, the replacement card has the same terms, unlike current tickets that apparently have an expiry date from first use. We only used one day. We will find out next month if they were telling the truth about the 2nd day having no expiry, since we will be back in Orlando then and plan to use up the one remaining day on each card.
I kept my original receipt to prove I was the original purchaser and the brochure that came with the ticket indicating that the tickets never expire, in case it was questioned. However, I did not have to show them. They knew exactly what to do and processed the exchange very quickly and we were very pleasantly surprised at how easy it was.