If the car has not been registered with the DVLA, you will need to apply for a registration certificate (V5C) using the information available from the old paperwork. You can do this by completing the V62 form and sending it to the DVLA along with the appropriate fee.

The V62 form is available to download from the DVLA website or can be obtained from a Post Office. You will need to provide information about the car, such as the make, model, and year of manufacture, as well as details about yourself as the new owner.

Once you have received the registration certificate, you can transfer ownership by completing the appropriate section of the document and sending it to the DVLA. This will update the DVLA's records and officially transfer ownership of the car to you.

It's worth noting that if the car hasn't been registered with the DVLA for a long time, it may need to undergo a registration inspection before it can be registered. This is to ensure that the vehicle is roadworthy and meets the required safety standards. You can find out more about registration inspections on the DVLA website.