An ancient Chinese Earthern jar - Motif study

I have had this jar for some time now and I think the time is right for me to share the details with my readers just in case there are other variants out there.

I welcome any feedback at traveltimes@gmail.com

 Twin dragon motif

Detailed study of the Dragon head

 The Dragon pearl

It is a four clawed Dragon

Detail of the eyes and eye brows

The traditional cloud motif surrounding the rim

View of the green glaze internal section

Some of the glaze showing signs of wear around the edges

A few hair line cracks around the edges especially in the places where the glaze is still intact

An unknown maker's mark on the base.

I wonder if anyone can help me identify this.

Overall view of the base

Detail of the base section showing wear

More of the base section around the edges

View of the side