Awesome, so I finally got this working on my 72 240z. I have the US "Flasher" switch from the early cars. To my surprise to toggle it on you have it in the UP position, toggle it down to switch it off. I didn't have the L-shaped two pin connector in my car, rather I had loose Green/White and Blue/White spade connectors near the bonnet release cable mechanism.
I'm not sure which wire is meant to go to L and which one to X on the hazard flasher can, both configurations work. The can gets warm but that's because it's the old style thermal version. I may replace it with a modern unit in the future, but I like the old Niles tube.
Now the fun part, cut a hole in the dash to feed the switch through into.*
I think the 3 pin connector is for Japanese Market Cars with the parker switch configuration in the console.
*Damn it, I tried my best not to balls it up.. But I'm not happy with the cut out. The switch doesn't come all the way through and the ring with thread that secures it in place doesn't sit on the outside of the dashboard to hide any imperfections in the cut.
US car reference photo, you can see the cut out allows you to see into the dashboard a bit...
On my car I cut a hole, it's a little rough. Although not seen in photos. I may try and tidy it up with a sharpie.