Dashed lines, by convention, indicate a mechanical connection (not a wire). The contacts shown at both ends of your yellowed dashed line are all inside the stock dash-mounted wiper switch, it's just been drawn on this schematic as being in two locations for the sake of clarity when analyzing the circuit. In other words, the pink-shaded "switch #1" and the blue-shaded "switch #2" are both inside the stock wiper switch. If you were to try to duplicate the function of the stock switch with two independent toggle switches the "pink" one could be a commonly available single-pole, single-throw switch but the "blue" one would need to be triple-throw, and that's not a common item. The pink switch would need to always be open until the blue switch was in the "off" position, because if it were shut while the blue switch was in a run position you'd have a short to ground which'd pop the fuse every time the wipers came to the park position.
This is where relays enter the picture, they can be used to make simple toggle switches accomplish the more elaborate functions of the stock switch.
Now, if you don't care about having the wipers park on their own and will settle for just manually turning them off at the right moment, you can simplify the wiring dramatically. Forget about the pink switch and its wire to 31b on the motor, forget about the black/purple-stripe 53a wire, and use a simple/common single-pole double-throw center-off toggle for the blue switch. High would be with the toggle handle up, low with it down, and off in the center.
Now, if you could find a double-pole, triple-throw switch that could handle the current it could be wired in thusly:
http://www.shoptalkforums.com/download/file.php?id=2182
...problem is, about the only DP3T switches around are made for electric guitars and aren't robust enough for this job.
If you were to use another double-throw, center-off switch for the headlights it'd just be up for Hi beam, down for Lo, and center off....but you'd need a second switch to run the taillights, and you'd need to remember to use it.
OR, use one single-pole on/off switch to feed both the taillights and the input of a second double-throw (no off) switch which would be used to select either Hi or Lo beam.
Either way's pretty crude and a bit awkward when the need arises to dim the headlamps for approaching traffic (without turning off the taillights and/or turning on the wipers should you hit the wrong toggle) but they'd get the basic job done.
A `69 should have a factory relay that does a dandy job of selecting headlamp Hi/Lo when triggered by the momentary switch actuated by the t'signal lever. My first choice would be to make use of those components, then you'd only need one SPST toggle to turn the head & tail lights on.
If you want to be able to turn the tail, and maybe front parking, lamps on without the headlights as the stock light switch does, you'll need a double-pole, double-throw center-off switch (one side for the headlamps and one for the taillamps)...up could be head & tail, down for tail/parking.
