I recall reading somewhere (the all knowledgeable `somewhere') that Beech had originally intended to get the BE76 approved for spinning.
According to the article they did most of the required work, including assymetric spins.
Not sure where I read it though.
Quite different to the US Army's stall testing of the Baron. The article I read about that said that failure to initiate a recovery within a 1/4 or 1/2 turn or so led to something not easily/likely to recover.
Wish I still had the articles.