I just went through this in Oklahoma. I don't know if it is any different in other states.
I bought a baja bug that had sat in the back of a farm for 15 years, and hadn't been titled in a long time, and the title was lost. I am using it as the pan for my speedster project. I didn't want to finish my car and not be able to register it (in 20 year when I finally finish it) , so I went ahead and went through the process on the baja bug.
I just filed a title 42 lean on the car, when they did the check to see if anyone had claimed the car missing or stolen, it came up negative, thus I have been awarded a title on the car.
It's probably a lot more complicated than that, but I just paid a company out of Oklahoma city to do it for me. http://www.needatitleokc.com
I think they only deal with cars in oklahoma, but I would imagine a company like this must exist just about everywhere.
I would call the local junk yard, and see what they recommend. When cars get abandoned, they must have some process to go through to title their cars, if they plan on selling them. That's a problem in just about every country in the world. I'm sure there is a loophole in the UK to get a title for that car.
Peace
Mark