Wow, Ivo, your addition made this topic even more confusing and interesting to me !
Then "of course" it happened I saw a similar vase like yours today on a fleamarket!
It was clear glass, dirty, in bad condition and also: very LIGHT. The feel was different from mine, as you can even see from the picture the glass on the mouth is quite thick.
However, as this was so very interesting I checked.
A very helpful person confirmed me the vase of this topic really is in Riihimäen lasi's 1967 product list and I have seen a copy of the sheet where there's a picture of a similar vase that is found on glaskilian.de site. "Prod. number 1434 - vase col. and clear - Sizes 300mm, 250mm, 200mm"
But: my vase does not have a neck as long as they do!
There's a pic on glaskilian site of two large, 30cm vases and then a 20cm = as high as mine, but it still has a longer neck.
I thought about the orange colour: By the time - 1967-1969 there were other models that were produced in clear, green and orange (strong and darkish like mine) eg. Nanny Stills Nebulosa, Fantasma, Stellaria etc. So in that way it would match. Now I am wondering, if this funny prunty/bubbly texture was produced in many models quite but not exactly the same? Now this would make three models: the one confirmed 1434, Ivo's and mine ? What do you think?