Thanks for all the comments and suggestions guys.
Gollum it did not get as far as a complete test, as in fairness the tester did not think it was worth continuing until some decision had been made on how we wanted to proceed. If we don't want it fixed then a fail certificate will presumably be issued and the car scrapped. Haven't forgotten about photo and will get one if I can just out of interest.
So from LazyDockers post it seems as though the dealer was right that welding is not on and only option is subframe replacement.
Appreciate that I could either obtain a new subframe at trade price through my friendly storeman at another main dealer OR get a used one from a breaker, then get either fitted. The problem I have with latter course is that I don't know of any reliable breakers locally or in a reasonable distance, so would have to go further afield and rely on getting exactly the right subframe and one that is going to last a few years. Add the cost of the frame, cost of courier and cost of fitting and I guess we are looking at about £300. At moment I don't think that's viable on a car that's only worth circa £500 (if that). Also bearing in mind that all this has got to happen before 28th March when tax, ins and MOT all expire and I do not have room to SORN it.
Given different circumstances, time pressures and my aches and pains with arthritis I would love to break the car for parts but as above that cannot be the option at moment so very reluctantly it seems as though it will go to Corsa heaven. I am open to offers over and above what the dealer has offered me as scrap value for it, so if any forum member wants to PM me, make an offer to take it away and then break it themselves please feel free to do so, but the time is tight and must be gone by 27th March at latest.