Many thanks for your observation. I realise the security of the vehicle is no way dependent on the door lock. However, the problem really is the latches that secure the hood to the bodywork at the rear. If i can’t undo these then I cant remove the hood to fit the tonneau nor can the hood be properly tensioned, relying on the windscreen frame latches to do so.
I meant undo them by jiggling. If you can't do it yourself speak to your local locksmith..theyll do it for you in ten seconds