For anyone looking for a tail gate for a 62-64 Country Squire is saw one on eBay, the ad says its NOS. I found it by searching Country Squire tail gate.
Are you only looking for a tailgate with good internal mechanisms? I ask that because as far as I know, the '62-'64 big Ford wagons all had DIFFERENT outer skins on their tail gates - most likely the same internals, but they didn't look the same from the outside. The differences are easier to see on a non-wood Country Sedan or Ranch Wagon: '62: '63: '64: You have to examine them closely to see the differences in where the body sculpting lines are on the 3 different years.
I was just quoting the listing I saw on eBay. I was browsing for tailgate parts for my 88 Country Squire and I saw that listing, I figured I'd put the word out there if anyone wanted to check it out.