The Herald is in a bad state simply because it is being readied for restoration!!. Considering the large collection of Airliners that DAS has to look after, I think that they do extremely well considering that these aircraft are looked after by VOLUNTEERS. I have no idea why there is no BAE 146, I suppose nobody has offered one yet.
I presume, because of your unhappiness with the state of the aircraft, that you left Duxford after giving DAS a VERY LARGE DONATION to enable them to restore the aircraft to your satisfaction.
Sorry. Thought your critiscism was unhelpful and ungrateful to all the people who TRY with limited means, to keep us happy!!!.