I am still not happy with the answer but there are worse things in life to worry about.
I hesitate to mention that the skin also coughs up a lot of files in the
res output that aren't actually needed for the album.
What resource files are needed depends, of course, on the options you've chosen, and on what objects are in the album. In my skins I try to control that, so I know how tricky it can be to do so.