English Heritage _sometimes_ are able to provide financial assistance for emergency stablilisation works, AFAIK, but I think it depends on the perceived importance of the building and how much they've got in the kitty (possibly nowt, as the heritage budget has been heavily raided to fund the Olympics!)
If collapse is imminent and there's a public safety risk, the local authority might help with emergency shoring, but again, no guarantees there - perhaps the threat of pre-emptive demolition might make them take notice.....
Other than that, there's the various historic/victorian building societies to try, maybe the Trevithick soc - if nothing else, these groups are more likely to know about possible funding sources, and you can but ask. 🙂
Follow the horses, Johnny my laddie, follow the horses canny lad-oh!