I've used Harry Berger's in Cheadle Hulme, Greater Manchester (25 Station Road, tel: 0161 485 3421 or 0161 485 7733). I'd recommend that you telephone first to check that the boss (Mr Berger) is around when you visit, and then talk with him about your requirements, emphasising that your precious vintage items require special care. He was such a lovely, helpful man and a fount of knowledge about fabric care.
A crumpled and sorry looking 1950s synthetic velvet evening coat made him pause. He said there might be no hope but he'd give it a go for me. It came back like new!
Also, I volunteer at a costume museum and the curator told me that they occasionally use a dry cleaner on Bridge Street in Manchester for less precious/more recent items. Having googled it, I reckon its Granada Dry Cleaners, 75 Bridge Street, tel: 0161 834 8947. They specialise in the cleaning of silk and theatrical costumes.
Edited for clarity.