Road Cycling“It is by riding a bicycle that you learn the contours of a country best, since you have to sweat up the hills and coast down them. Thus you remember them as they actually are, while in a motor car only a high hill impresses you, and you have no such accurate remembrance of country you have driven through as you gain by riding a bicycle.” -- Ernest Hemingway
To my knowledge almost no parts were ever commonly made in the U.K. when Imperial units were used. Parts have always been commonly made in Italy, France, Spain, and Asia where metric units are and have been used. That's why you only need metric wrenches.