Can't help you on that particular watch, but you seem to have listed most of the obvious things. I had an Italian sold Explorer and the books were in Italian, which on one hand was great, but completely unreadable to me. Be aware of the dates on the books, they need to be around the same date as the watch, logically printed before, but if the set was made up later they could be later books.
I recently parted with a 1999 SD and both books were dated 1999, one was Jan and the other Sept, so you could accept that those probably came with the Watch.
Once you know which books (correct cover etc) and boxes that you are looking for they do appear on the likes of e-bay.