I am using an old paper, published in 1986. It is in the form of a "Letter to Nature" (which is a scientific journal). It doesn't appear to be typeset in TeX, at least not TeX as we know it today. Furthermore, it is a scanned copy, so it is just a image, embedded as a PDF. The lack of multiline equations, and highlight-able text is getting to me.
I'm considering re-typesetting it myself by hand in LaTeX (it is quite short) for my own benefit and understanding.
The paper is still being cited today, and is used in university courses to teach the subject. It seems a waste to have gone to the effort to retype it neater, and then just leave it in my draws. If I re-typeset it, what can/should I do with the new version?
Can I host it online myself (giving full credit to the authors)? Should I send a copy to authors, for them to do with as they will? Are there issues with the fact that it has been published in Nature? Perhaps they have some copyright on it?