There has been some questions about connection changes 67-68 and 69. That 68 FSM diagram may be wrong. I don't have a 68 to compare with.
Here's a 67-68 (and probably 69) replacement switch with the posted diagram from above and as observed it does not match up to the labels on the start, Accessory and Ignition 2 (start) terminals. The wiring should match as drawn below.
Here is the factory '67 connector. It matches the SMP replacement switch marking