This 1900 H.M. Caldwell Co. Rubaiyat looks like it could be from their Alcazar Classics Cordon Series. The LUCILE Project’s website puts that series at 1906, but the book is copyright 1900.
The cover is kind of shiny, with floral decorations and a picture of a woman that is raised off of the cover. Like this Hurst edition, the cover style feels incongruent. I actually like it and it feels well made, but it definitely does not fit the Rubaiyat aesthetic.
A website visitor reached out with this copy and I purchased it from them. Thank you!