I can't see any differences in those pics. I'd still like to see higher res shots, but I'm starting to think that the "volume" control (which is basically a variable resistor) on the stalks I have aren't compatible due to the fact that they're built to work through a the time delay unit, not a wiper amplifier. What's the difference? I have no clue, but I'm hitting Radio Shack tomorrow for a 100k ohm potentiometer.
This gives me inspiration....
Variable-Speed Intermittent Wiper Control although I think all this guy had to do was swap in a similar year 626 switch, but what do I know?