Hi guys,
I am importing a LHD 126p to the uk .....
This subject has been very extensively discussed on this Forum in recent years. As I recall (but don't quote me) what is needed may vary depending on what year your import vehicle is, and hence what were the pertaining UK regulations at the time (since the vehicle will be allocated an age-related UK registration mark). Then again, regulations change with time. So that's helpful, isn't it!

You need to search this Forum for the extensive experience of others who have successfully done this, and it would be worth also checking the latest UK government guidance:
https://www.gov.uk/importing-vehicles-into-the-ukBE AWARE: you can be fined £5 PER DAY if you are late in telling HMRC what you're doing, and you only have 2 weeks in which to notify them. So DO check out the government web site SOON !!
From what I can recall of various posts over the years, MoT testers' familiarity with and interpretation of the rules for testing imported vehicles can be pretty variable, so be prepared to 'shop around' a bit if you have MoT pass problems.
Good luck !