Me, 72 in a few weeks. This was last October on the parkway. I ride selected sections of the parkway for 4-5 weeks every year. Living in Fl it is hard to train for climbing but if you have the gearing and the state of mind it is pretty easy as long as you don't mind being passed buy locals even older than you.
Climbing up the spur road up to Mt Mitchell two years ago I was passed by a butterfly, really! I took a video of it to send my wife.

My favorite sections are the Cherokee to Mt Pisgah, and the climb from Town Mountain Road (Bull Gap) parking lot up to Craggy Gardens and then on to Mt Mitchell (if it is a feel good day) The ride back down from Craggy is very sweet. I'm a slow down at 30 mph guy, the locals are pass motorcycles kind of riders.

That is my new to me Domane Disc w/Di2 . It's geared to climb and the Hydro brakes are so good on the long downhills