Hi
Had this a few years ago, advice from my solicitor was you have wright of leian (spelling !! ) on the CURRENT job, so hold on until paid. But NO right to hold for previous work. The receivers in my case tried to make me release the vehicle (told me pack of lies ) but phone call from my solicitors to them money arrived 2 hours later !!!!
This was 15 years ago, so may be out old date so please check

Aidan