Willy Pogány’s work is no stranger to these pages, and I did once link to scans of his illustrated Rubáiyát although the site where those images were posted has since migrated. Pogány’s edition, which dates from 1909, presents the quatrains in beautifully lettered and decorated pages separated by watercolour plates. The Persian details may be Pogány’s own approximations but he thanks Arabic scholar Dr Julius Germanus for his assistance with the book. Some of the pages at the Internet Archive are the worse for wear but this is one edition where every page is worth seeing. Browse the rest of the book here or download it here. (There’s also a second Pogány edition from 1930—not 1900 as the site claims—which is worth looking at but seems crude in comparison to the earlier book.)