Thank you for contacting Mearto and I apologize for the delay. This is an ink painting of Quanyin on an elephant. I believe it is Chinese. The inscription reads: 存古斋 or 存古齊 (Cun Gu Zhai). I was not able to find much; there is a book of prints that may be related. I put a link below. Another artist by that name is also linked to below, though the work is different in material.
It is a very nicely made painting and I recommend sending an image to a few auction houses to see if you can get more information that way. Christie’s and Sotheby’s are good places to start. Without a known artist, the market value should be between $500 and $1500. Please let me know if I can assist further.

Maybe related book
http://book.kongfz.com/3075/442637291/

Porcelain, same name
https://www.artfoxlive.com/product/434806.html