It's easy to tell the difference on the hood. Look at the square area where the latch goes in. On a '67 hood this area is flat. On a '68-69 hood this area is angled downward.

However, you said it gets farther from the safety catch. When you look under the hood, or swipe your hand or an object past the latch area, is there anything still making contact? Or are the hinges just sticking? Hinges are a common point of failure. If they are too stiff, forcing your hood closed can buckle the sides of the hood. If they are too loose, the hood won't align properly when closed.