For drivers side horn I found it's easier to reach up from under the car through the battery tray to access it. As a "temporary" fix for my last MoT/testing I got a plug kit and crimped on the female prongs and then pushed them onto the male...

I think it was an option for duals until ~98 where it became standard. As with everything Landy at the time, nothing seems to be set in stone and anyone can have anything if they ask for it. But not sure what the score was for Japan. They had...

If it's a jap import that'll be KM which is about 65k miles. But that is a pre 99 P38 for sure, so a bit sus to claim it a 2000.