I imported my US-spec W111 from Canada to the UK with Cars UK (
www.carseurope.net) with good results.
Costs in 2018, FOB Felixstowe were
USD 4000 = Eastern Canada to Felixstowe in dedicated container
GBP 650.00 = UK Arrival Handling
GBP 250.00 = UK Customs
++ UK Import Taxes Payable to HMRC at 5% (Payable on vehicle value & transport fees)
I arranged UK insurance with Haggerty once the registration came through. Fee for broker to register the vehicle in UK was GBP 500.00 + VAT. They also arranged for a MOT. You will need an ORIGINAL registration document for the DVLA and a UK address in order to register the car in the car. If you know you are doing, are in the UK and have the time, you can do this probably yourself.
Hope this helps. PM me if you want specific info.