Where to publish comments on a scholarly book? The past year, I've been reading a mathematical manuscript from a well-known university on a particular well-known, graduate curriculum subject. The manuscript language is not English. One can imagine a manuscript on, e.g., Algebra in, e.g., Spanish in the form you usually give it to your students before you hand it over to, say, Springer.
At a certain point I found myself latexing my comments; now they have a subjectively better quality than the original manuscript, and they can be used as auxiliary material for everyone working with that manuscript. The comments are in English. Today, the manuscript volume is around 300 pages. The comments are around 50 pages, are 90% self-contained, and could be potentially turned into a small booklet. The comments are evolving and growing. The comments do not repeat any manuscript material except the usual stuff such as defining notation and claims which deserved new, better proofs. Subjectively, the students who wish to comprehend the manuscript need such comments or equivalent ones.

I have no time for 100% self-containedness (which would take me a few weeks), not even any time to find a coauthor (which would take me at least a few weeks till infinity). But I do have time to put the booklet into a publishable format, which will take me less than a week.

The author of the manuscript is out of question to be contacted in any way (the reasons therefor are private and cannot be elaborated on here). 

Now I learned that the manuscript is in the process of being turned into a book by a well-known research publisher. What would be the best way for me to publish my comments 


to get research credit by entires in traditional listings of research papers/journals/books,
to get an ISBN, if possible?


I would like to know whether such auxiliary material is typically accepted by an established research publisher (say, AMS, or Springer, etc.) and, if so, what are the typical conditions. Or, otherwise stated, if it is possible to get it published at the same publisher as that of the manuscript at all or whether I should take another one?

PS. This question contains no personal details in comparison to a previous one, which I deleted.

UPDATE: It is no more my intention to earn a bit from selling. It would be just a moral support to get 1 cent per sold copy, but nothing else.
From your description, about the most it sounds like you could do is post your notes online.  

Why?  Your notes are not self-contained and I haven't seen things like "study guides" published in concordance with graduate texts, which indicates that there's little market.  Even if there were some market for this, if you don't have time to make your notes self contained, you likely don't have time to get them in a publishable format either.  In any case, the amount of money you would get should be minimal.  Grad texts are not a cash cow.  I also don't see much advantage in an ISBN, but you could get an arXiv id if you post to the arXiv.

Free online notes can give you just as much if not more "recognition" than publishing, depending on the situation (free notes are easily accessible, hence can get wider distribution).  I've done this for some courses I've taught, and while I don't have any measure of how much recognition I'm getting (nor is it that important), sometimes I meet people at conferences or what not and they say nice things about my notes.  Conversely, I've gotten a good impression of many young people by coming across some nice notes they've written.  

Of course, if you do this, you should make sure to give the author due credit and that you will not be infringing on copyrights.  Note that the presentation of material and choice of definitions is a big part of the originality of the author's manuscript.  I spend a lot of time thinking about order of presentation when I write notes.