We have the following original fencing manuals available in PDF and bitmap form. 
These are complete and unabridged facsimiles of the original manuals.
(I believe it is essential to read the whole manual since only then can you fully appreciate what the author had in mind, and understand the thoughts and ideas behind the basic techniques as well as the mindset of the time.)

Joseph Swetnam
The Noble Science of Defence
(8,643kB)

Giacomo Di Grassi
His True Art of Defence
(4,440kB)

I am indebted to the late Patri Pugliese for being able to supply these manuals.