Heisterholz Keramik - Traditional Fireproof Coffee-Pot (165/4R)

Basemark: Waffelboden in the middle marked 165/4R 1,0l

Maybe this piece is by Waku? or by Porta-Keramikwerke J. Brauers, Porta-Westfalica-Barkhausen ???

 

Update: Heisterholz Keramik! Found an item with a label and very same numbering and shape.

Done