Here another original and very subtle sentence by me:
"You can't download what hasn't been uploaded"
Such a stupid sentence hides a little bit of truth: many equitation classics haven't been uploaded at all. They are a very specialized issue, with a VERY low number of really interested readers. But... anyone of us perhaps could have an opportunity to access to an old classic book, and anyone of us - if he/she has a little bit of tecnology skill - can take decent scans or pictures of such book and upload it into the web. It's not so difficult. The really important issue is, to be sure that the book is in PD - Public Domain - t.i., it is no more covered by any copyright. In USA there's a very simple rule: anything published before 1923 is PD. In Europe, things are a little bit more complicated: the main rule is that the author died from more than 70+1 years. Take into account that translator too is "author", so, if the book contains a translation, you have to consider the data of translator.
Briefly: if you are so lucky, to have access to an ancient book printed into XVII or XVIII century... please scan it! It's PD for sure! Most of books printed into XIX century are PD too, and many printed into first decades of XX centuries too.... please take a look to the best biblioteque of your town, and think about any friend who collects old books... some interesting and unexpected findings are waiting for you!
I am in touch with the owner of a incredible personal biblioteque, containing some thousands of old equestrian books. When we speak about XVI century books like those by Corte, and Grisone, and Fiaschi and so on... well, he owns one or more copies or the original books. He owns those books... but lacks time to scan them (nor, I guess, he would like to allow any one to touch them!). I hope, some of you could be more lucky.