The major differences are that the Fed was perhaps somewhat less transparent about how it derived the range for M2 and did not update it regularly to maintain an estimated consistency with an unchanged trend inflation rate objective.
In the 1940s and 1950s, large-scale units of fixed machinery - such as blast furnaces and assembly lines - more normally characterized manufacturing capacity. Many observers have argued that, because this capacity required long lead times to manufacture, test and install, available capacity was easier to measure and slower to change.