World Best 400m Question

Hi guys, I am a stats fan and I am trying to get clarification of something related to the Decathlon. I have been reading up on a British decathlete from the 1960's and 1970's called Peter Gabbett. In several places I have read that his 400m at the Munich Olympics, 46.1s, was a world best for a decathlon but I have been unable to get verification from an authoritative source. So I have two questions:


1) Was Gabbett's run a world best for the decathlon, either overall or for non-altitude marks?


2) If the answer to 1) is yes, when was it beaten and by whom?



Many thanks,



Numbers