Thank you so much for your contribution, Ivo!
Interesting to learn that the amber colour is normal in red glass (I did have doubts that there are 2 layers).
But there are really significant differences in the pattern of the two vases. So why would they use different (steel) moulds for the same design?
My glass 'bible' (20th century factory glass) says that Christer Sjögren developed a range of vases in 1965 with textured surfaces, which were blown in wooden or grafite moulds...
(But who knows if my vase is part of that range...)
So, still a lot to research

Michael