Good Evening. The problem you have is similar to the one I have on my 2004 MG TF which I purchased last May. The securing strip on the driver's seat cannot be put back in place. I have come to the conclusion that the best option, as I intend to keep the car, is to exchange the seats for leather ones ( possibly second hand given the price of new ones ) - the current seats are cloth and although they are in reasonable condition for the age of the car they look a little tired and there is some wear on the driver's seat. Hope this helps you in reaching a decision. I have to say that you took a very good photo of the problem.