That looks like a fair bit of money just in the fuel lines. Are you keeping a count of what the car has cost you?
I could have helped you there if our wiper motors are the same type - I did it on mine years ago. [After similar head scratching] I used a three position toggle with six pins. Both high and low wires have to be grounded to get the low speed.I’ve at last worked out how to wire the wipers through a toggle switch. Onto the front lights and engine wiring next.