Hey Jonathan,
Here's a tech tip Woogeroo put together. Use some of the tips to asks sellers questions and where to take pictures for you to see if there's real rust issues. The 60-66 trucks have specific areas the like to rust out at. If these areas are good and clean, you may have found the right truck to buy. Just don't settle on a truck just because it's available at the time, the right one will come along,
Scott