This rare book needed some extreme intervention to restore.   The book was held together by tape at the spine, as each folio was split and extremely brittle.  I treated the cover and interiors with solvents to remove the tape and tape stains.  Fortunately for me, I did not need to bleach the tape stains out, as the solvent baths removed the staining as well as the tape itself.  After tape removal, I leaf-cast each folio and the cover and then all areas were inpainted to recreate missing artwork and graphics. Each folio was then refolded and the entire book reassembled.