I really struggled in Yorkshire.
I got licky (???? I meany LUCKY!!!) with the RSPCA in York, but I did find that quite a lot of websites listed don't work, or the phone doesn't work, or there is never a reply to emails. We almost went visiting relatives in Norwich and Reading as a pretext for visiting rescues, but there were problems with going so far afield with the home visits. It would be nice if you could get a "home visit certificate" like you get with Police checks for teachers etc - proof that you are a good person with a date of issue on, so people can see how long ago you were checked.
Keep on trying, there is a pig out there for you somewhere!