On one hand, yeah it's worth a regrade considering the differential. The other consideration, though, is that you might face a tough task considering the value involved. But it is an old green holder....
I'm not sure what you mean by tough task because of value? My father gave me all the green label peace and Morgan's so I'll leave them to my kids to squander and sell when I'm worm food.
Because the price would jump so much, a TPG might be inclined to grade it rigorously. But a 65 in an old green holder is nothing to sneer at, for sure.