Before revision: BR planners realised early on that it would be quicker and cheaper to buy an existing system, rather develop one locally, even if that breached the British Government's requirememt for nationalised industries to 'Buy British'.
After revision: BR planners realised early on that it would be quicker and cheaper to buy an existing system, rather develop one locally, even if that breached the British Government's requirement for nationalised industries to 'Buy British'.