Grassy, as far as headlights, you don't really need to replicate. I would run relays anyhow, which means that lighter duty switches could be used. There are many, many ways of setting this up. On my old Landcruiser I used a center off/ DPDT (double pole, double throw) toggle switch. So that has 3 positions---center off, and up, and down. This will have 6 screw terminals, and is essentially 2 separate switches side by side.
Here's how I wired it. I wired park and tail "on" so that was easy
Feed headlight fuse to one center terminal, tail fuse to the other.
On the tail side, hook both outer terminals together, and wire that off to tail/ park lights. This causes the tail/ park to be center off, tail/ park ONLY "down," and tail park (and head) "up."
So on the headlight side, you are only using two of the 3. fuse / power to center, headlights on the terminal that is activated with toggle "up."
For dash light dimmer, I'll have to measure the resistance of the dash dimmer. You can buy a rheostat from an electronics supplier to do that
Wipers might be a different issue---the dammed things are just wired weird, with some "ground leg" switching in some motors. Might just be better to adapt a factory switch
