Yep, 67 is 2 speed. The switch contacts also indicate Packard style connectors. Neat that it has it, but MAN, these extra options are mind-numbing lol. Also on the "list" is one of your Demon VR, set of Autometer triple gauges and a hidden stereo. This "seamless" dash swap ain't gonna be so seamless lol.
I never dealt with rear defroster in a-body. If 67 was only 1 speed blower and switch, 2 wires were enough. I did see high and low speeds labelled in the 68 drawing.