I had just finished adding the latest version of my largest 'furniture' model*; it contains a couple dozen defined materials, of which I remap at least half to a new texture. I know in at least one case I made use of a self-referential texture -- that is, under 'Materials,' I opened a defined texture, selected the existing texture in order to add it to the array of thumbnails, and clicked 'OK'; I then opened another material definition, clicked 'Texture,' and selected the thumbnail I previously added.