I retired in 2010 at the age of 62 1/2 and we have punched about 80% of our list. Our list was more extensive than yours, but has many of the same places.
We did Ukraine, Russia (including a river cruise) and the Baltics, China, SW India, Singapore, Bali, Japan, and most of the countries in South America (except Brazil). Also, visited most of Europe (we lived in Germany four years).
We have the East African safari in August and did the Galapagos Islands (Celebrity cruise) just recently.
Don't plan to do Cambodia, Vietnam or Nepal and Antartica.
Suggest doing a cruise around the Horn of South American with several days in Buenos Aires.
We did Cusco, the Sacred Valley and Machu Picchu in 2019. It was great, but we were in our early 70s. Still, we are fit for our age. We took altitude sickness pills and managed fine for four days, but at the end were very tired. Suggest doing this when younger.
PeruAgency was our tour company and fantastic, especially for the price of $799 pp.
Alaska, do a cruise that includes Glacier Bay and the Hubbard Glacier, as well as post cruise trip to Denali.
Norway, we did the north cape cruise all the way up the coast of Norway, amazing. No hurry to do that, it wasn't stressful.
In Australia, be sure to do Melbourne as well as Sydney and the Great Ocean Hwy south of Melbourne as well as the Phillip Island penguin thing. Also, do the Blue Mountains west of Sydney.
I did Egypt and Israel before I met my wife, and we plan to do those since my wife hasn't done them.
Definitely do Egypt in the Winter. Do it on a tour and do a Nile cruise. Don't try doing Egypt on your own. You need the security of a tour.
Israel is fantastic.
Your may have done the big three in Italy already, Rome, Florence and Venice. They are amazing.
Don't ignore Great Britain and the countryside outside of London.
Another tip, the older you get, the less you will want to drive a rental car. If you want to drive around in a rental car, don't wait. In fact, some countries won't let people over a certain age rent cars.