Stoneware Modernist wall pocket vase

I have this lovely stoneware Modernist style square wall pocket, which is also free standing. It stands over 12” high with an assymetrical rim, and beautiful drip glazes. The inside is glazed and watertight. We wondered if anyone can identify the maker of this piece. Belonged to an elderly relative of my husband, but that’s all we know. I appears to have some age and may have had a label on the base at some point. Looks like there is some sort of mark in the base, but not sure if it’s my eyes playing tricks on me! I toned down the colour and the light in the last photo. Can you see anything??!!