If you are a passionate hobby interior designer - go to the Fulham DIY shop.Going there most of there customers are electricians, builders etc. who go there as a regular to order wholesale.
Before the smoking ban they even were allowed to enter in with their light cigarettes - that is how easy going this place is.
From the bottom to the top there are shelving with anything from nails, toolboxes, tubes, window handles etc.
I once made my way there as my window screw broke. They had several versions of my broken example and I could close my window in a couple of hours again. That was a relieve.
They also have more stock in the backrooms, therefore whatever you need, ask - they might have it. What I appreciate, even though there is a counter where you get served, you are allowed to have a look around. The service is very polite even when you only buy 4 screws. read more