Hi Harry - welcome to the forum 🙂
I use two people depending on the extent of the work needed.
For general setups, electronics (guitars and pedal as well as amps) I use https://www.facebook.com/proaudioengineering which is Run by Michael Owen (not the footballer ha!). You should be able to get Michael directly on: 07492448840. He works out of Muthers Studio ( http://muthersstudio.co.uk/) in Digbeth.
For more advanced luthiery, fretwork and customisation I rate Bob Barry Guitars ( http://www.bobbarryguitars.co.uk/) extremely highly! Bob is a master, but probably over kill for the issue you described to me via email (collapsed pickup).
Hope that helps!