I would like to (re)submit a paper with a short cover letter, explaining the changes I have made. However, the journal only allows me to upload one file. As the main article will use the journal style class, and so forth, it's not really practical to use the 1st page for the letter (or is it? Could I reset the page number etc. etc.??)
Instead, could I create, say, two PDF files (one the letter, the other the article) and then somehow merge them together?