Rare little item - probably Strombergshyttan by Gunnar Nylund!?

I have discussed this unusual little vase with a glass expert, and we agree that it is probably an object from Strombergshyttan, designed by Gunnar Nylund. The underlay in tinted blue/purple-lime is something I remember from my childhood in Strombergshyttan and the shape might match Nylund style guite good. I also have a weak memory of having seen this special model in several sizes at the Stromberg exhibition hall in 1960s, among other objects by Gunnar Nylund.

We can not find it in the directories from 1954, 1962, 1972 and 1977. But I believe it's from 1955-60, and certainly quite rare on the market today. I hope to find som more Stromberg catalogs from late 1950s/late 1960s and after that, get the vase confirmed as a Stromberg model. If you can help us already, it would be grateful!

Height: 10,4 cm
Diameter top: 9 cm
Diameter of base: 4,4 cm