If you think a car has been awarded an MoT when it should not have been you can complain to www.vosa.gov.uk and they may investigate the MoT station. However, since you did not pay for the MoT (you merely bought a car privately on the strength of it) I don't think you can demand compensation from the MoT station. However, if you find that the vendor was a trader posing as private, you can sue him and have him prosecuted by local Trading Standards. All that said the car was dirt cheap and 12 years old, so a court may take the view you could expect problems.