you can try sendean in soho, website below, I've had a couple of old camera's fixed by them, they are not exactly cheap as chips, but get the job done...
I deeply hate that place... they kept me waiting for 3 cameras to be cleaned and checked for one week, then said it would take other two weeks. then I found out that the cameras were in Tunbridge Wells, I had to get them couriered back on my expences, sent out to John camera repair (east london, amazing guy for medium format and mechanical cameras) got them back 3 days later (over a weekend) for a third of the price that sendean cameras quoted...
I deeply hate that place... they kept me waiting for 3 cameras to be cleaned and checked for one week, then said it would take other two weeks. then I found out that the cameras were in Tunbridge Wells, I had to get them couriered back on my expences, sent out to John camera repair (east london, amazing guy for medium format and mechanical cameras) got them back 3 days later (over a weekend) for a third of the price that sendean cameras quoted...
I hate them.