I was recently advised that Johnsons dry-cleaners have a specialised leather & suede centre which is very well regarded (Long story: I was referred to them by a company who sold me a leather jacket which has torn and they are wanting Johnsons to inspect it to quote for repair). But I don't think there's a branch local to us and I have no idea about prices...
I inadvertently dropped something greasy onto a suede skirt when in a restaurant.
I took the skirt to a dry cleaner in Jamaica Rd. SE16.
I can't remember the name of the place but it's close to the junction of Drummond Rd. SE16, in the parade of shops that has the Post Office in it.
They said that it would have to be sent away, it would be around a week, and would be £40.
I accepted that, and it came back looking as good as new.