It was common knowledge and confidently taught that things fell at a speed proportional to their own mass until someone actually bothered to carry out the experiment. Surprise surprise, common knowledge was wrong. Things fall with an acceleration determined by gravity.
We are in a similar situation with the 19th century flute. If you read through the available literature dealing with the 19th century instruments, you will notice a pattern. All the writers repeat each other. Again, and again. Indeed, they even reproduce the images from the books of previous writers. There has not been much in the way of original thought since these instruments were first made.
This might not be a problem if the original writers were accurate, unbiased, comprehensive and knowledgeable. As it turns out, this does not seem to be the case. Consequently a lot of what we are led to believe today is simply wrong.
There is a great need for serious original research in the field of 19th century flutes of the quality that Grant O'Brien put into his researches into the Rucker's family of harpsichord makers. As a craftsman maker, I do not have the resources to carry out that research. But I can at least prick a few balloons and hopefully someone better placed will hear the noise and come along to investigate. In the meantime, I hope you find these papers useful.