xj900kaz

The vendor is telling lies. If its an export vehicle it is either already registered or the shaken has been cancelled ready for export. Either way getting a spare key is no big deal. PS--Im othjer end of the world and import around 30 cars a month from Japan 

When you look inside the drivers door "hole" you will see a white sticker at the back --on it will be the factory wheel/tyre size.

 I suspect it is 235/50/18.  If you have bigger wheels with lower profile tyres it will make the ride more harsh -eg 235/40/19 

  if the wheel/tyre size is factory then shine a torch Up under the fender behind a front wheel.  The shock absorber sits there.  

   You should see a black shock and black coil spring. If either are any other color then that means after market suspension has been fitted.

    Whils in there -towards the top of the shock inside the spring is a rubber boot. If its torn or just loose slide it aside and check the shock isn't leaking oil.

I'm guessing that the conversion involved removing the Jap radio with limited band width and fitting one with fall FM band width and a reverse camera. What you will find is that you need to look at the back of the radio itself.Modern ones have  plug in wiring that runs to the wheel controls. Others will need a kit. to work.