I appreciate your concern over my research skills. To explain, I am a scientist by education, a martial artist by training, and a knowledge junkie by some unexplained genetic anomoly. I research everything before I speak of it. My friends hate that I am so cautious in both speech and written word, because I make a very strong effort to make sure my facts are straight before I speak. There are three things I have spent my short 31 years doing: researching the history of world religions, researching the history of Martial Arts, and reading dictionaries and encyclopedias. Yes, I am a geek; I'm a social leper, but if it's one thing I know...it's my facts...to a fault. My wife hates my lectures.
So, I suppose alot could have changed since the 80's. I suppose it's possible that the original style is taught as it was originally intended.
To site your examples of names for my 'research'; names I have been aware of for years, but let's break it down for a second.
The current Grand Master Dr. Masaaki Hatsumi, knew and taught Stephen Hayes, who later came back to America to "teach" others this ancient artform. I agree to that, but it stops there. Quite honestly, considering the bulk of todays current Martial Arts system, there are only a handful of styles that have stayed "original" outside of the home country that they were developed in. Outside influence and ones own development and manipulation always change the end product.
All that said; I would never consider learning such a refined and splendid art as Ninjutsu from anyone other than the Grandmaster. So, this could just be a prejudice on my part; for which I apologize. I'm not a Martial Art purist by any means, I believe that there is always room for personal interpretation of any art form. It wouldn't be art if that were the case.