Ive just been back there today and I see what you mean 'bout that crypt!! Ab-sol-ute-ly pitch black. Gave me the jitters even in bright sunshine.
Its a lovely building - some brilliant stonework (if you like that sort of thing) Scum vandals who have damaged it/grafittied it/left lager cans there make my blood boil though...
Really hope it gets renovated, at least its a Grade II (I think) listed building so hopefully it wont just get knocked down to build an estate or something...
I don't think it well. Mind you Seaton Delaval Hall. (The Mausoleum is in its grounds) was going through very bad financial difficulty. which would have either seen it left to go derelict or something. There was a lot of fund raising to raise cash for the national trust to buy it. I'm not sure whats happening with it now. I've confidence that Sausage will know where its at though. He's like a giant news thesaurus