You are ignoring data sets that go back further from Aircraft and Ships and ocean buoys and there are more types of readings available and you are assuming tha

You are ignoring data sets that go back further from Aircraft and Ships and ocean buoys and there are more types of readings available and you are assuming that I intended you to stop at 4 or 5 decades ago and go no further! It's your lack of usage of that ACE metric and other datasets that are allowing for even finer grained tropical cyclone intensity measuring analysis. Your extremely limited sampling of the historical data sets will not pass muster in any peer reviewed scientific publication or Academic setting and I'm not leaning either direction on the matter but to say that your sampling method is much too cursory to pass any stringent review process.