You can easily change this if you feel you want to. All Ma did was use the very same headlight switch, and move the "park" feed wire over to the "tail" terminal in the headlight switch connector. You don't even need to move the wire. You can just get back in the harness a few inches, and splice them together.
Keep in mind, though, that 67 parking lenses might be a bit hard to find. I don't need to melt mine because I like to show off the bulbs, LOL