Re: Pre War Aikido, 1930 through Iwama period
The field is not so sparse. O Sensei's life is quite well documented (through writings, film, pictures, drawings, testimonies...) thanks to the work of research of a few, and is still today the source of fruitful debate and analysis.
Just ask the practitionners of many chinese martial arts if they would not gladly have the same amount of information about the founders of their arts. Most of the time they have to satisfy themselves with fragments.