@Balthazar
Its from the 1980s.
@Chadrinkincat has a pot with the same shape, and he got multiple pictures of it on his Instagram page:
Teapot photography is divided into 2 school of thoughts... to catalogue your collection or for artistic illustration. Both uses different lighting setup. To catalogue it use a wine wooden carton and 6 LED table lamps... not the best but works for me. I use my iPhone as camera.
Looks plausible. The base seal is called "Jingxi Nan MengChen zhi", used up till the 60's. Might be quite collectible.