thought about #5; however, it wasn't a simple task to complete. Good suggestions, thanks.
Michael, I am still not clear on whether the difficulty with this suggestion was in identifying which images need to be watermarked SOLD or implementing the watermark?
Marking itself seems fairly straightforward. Either GD could be used or the image could be displayed as the background of a table cell - then the word SOLD could be printed straight over it.
So, I am not clear exactly where the difficulty lies.