Just a thought and I don't know if there's any mileage in this, but had a shower job to do near Wallington (Surrey). Got there to find customer had bought a 9.5k shower. The electrics needed uprating (originally 7.5k). Could I find anyone with the right bits I needed?? could I heck. It took me over an hour to locate a merchant with the replacement stuff I needed, despite Google, etc. Where I am getting to is... is there any merit/way/good idea(???) to have a list of post codes and neareby merchants/suppliers? Is it viable?