Here's an archive that has 3 different versions for ROTS (including the original art before they redid it to make Vader's head larger.). It also has TPM, although the contrast will need to be adjusted. I don't have a good version of AOTC.
http://www.mediafire.com/download/3x19w62sjblzaen/struzan.zip
Video Collector did nice scans from an art book for his custom bluray covers, so you might want to pm him and see if he still has those.