I reckon the big reason for all of the cooperation is that there was virtually NO competition. Sure we tried to outdo each other but the Industry was so heavily regulated that we could not lose much at all by helping out.
While I appreciate your post, and your point of view, that is very cynical and certainly NOT the reason us Engineers helped each other back then, when we had finished our own work.
Nor was it anything to do with Industrial matters, Unions or Associations, it was just what we did.