I just though I'd let you all know about a company I've found called
Spalding Fasteners, who will supply imperial thread fasteners in small amounts (and in stainless too if required). Which is kind of handy for any any classic mini owner to know!

. P&P rates are reasonable too, they supplied me with the four stainless bolts to hold the fog lamps to the rear valance for £2.39 including delivery!