I spoke with someone at the Church today and was quite disappointed in the reason for this particular clock being stopped. The Church is the sixth and final London church designed by the leading architect of the English Baroque, Nicholas Hawksmoor, and is quoted in the Guardian as being "One of the capital’s most wonderful buildings."
Although the Church had a 5 year restoration ending in 2006, the clock is 'erratic', and when speaking to the administrator she essentially said that they're not interested in restoring the clock to proper function. They don't consider it a problem, which I find utterly amazing - this is a phenomenally important building, with a large public clock which has no excuse for being in disrepair.
I have asked to speak to the Rector and the administrator has said she will pass along my details, so I'll hopefully update you on this one soon.
Posted by Alfie