I was going to reply to this when I saw the thread was bumped last night, but another posting with higher priority caught my attention.
I see the “Lewis number” has been applied to the title of the one Revueltas work that IMSLP has, which makes this less of a problem for cataloguers should the numbering change in the light of subsequent research. It’s normal to issue fixed numbers at the
end of a research process, not in the middle — and I am well aware of having been guilty of that sin (of premature publication of unfinished research*). In my opinion it would be better not to append these to the IMSLP work titles presently.
Cheers, Philip
* In my own case compiling a numbered list for the British symphonist
Havergal Brian, there were three prior worklists (un-numbered) and several reliable biographical texts as well as access to a very large number of written articles that I was able to draw on, in addition to providing fallbacks within the numbering system to admit several new discoveries without abandoning strictly chronological numbering. As a result, with the exception of one problematic area of works, the numbering I assigned has been “stable”. I don’t wish to question the thoroughness of Nick’s work (I’m aware he’s bilingual which would be a distinct help), but there is clearly a lot of research that has been done already and I wonder how much of it has been consulted to excavate references to minor works that may not have been noteworthy to mention in other contexts: the mere existence of these would upset a strictly chronological numbering.
As for my work, it has been officially abandoned (or postponed, at best) for a variety of reasons, the chief one being that I would have had to move to London to conduct the research properly in the depth it demanded as well as a view to doing it efficiently (and while that was a plan back in 2006 or so, it did not eventuate).