Thank you both for your thoughts, greatly appreciated (as always

). And sorry for the delayed reply...
I totally agree that the white lining gives a special look to the decor, almost like porcelain.
@Sue: I don't think I would call the vase is a miniature, as this shape was in the catalogues from the late 1920s until 1951 in exactly this size.
@m: The pontil finish of my vase is quite similar to the one in the ebay link, and not really different from some of my other Ikora pieces.
Regarding the date Zeller gives for the vases: to be honest, when it comes to Ikora glass I don't take the date auction houses or ebay sellers give too serious; they all claim 1920s or 1930s, even if it is a clearly recognizable post WW2 piece.
The book is my number one reference here...
(And I am convinced like you that several pieces in that Zeller link are not Ikora glass at all).
What is IMHO the strongest point that these white cased pieces are post war production are the two green-and-brown vases in the second row of the Zeller link; this is definately a decor and colourway found only in the post war catalogues, and one has the white lining.
I just wonder if these pieces in question were perhaps produced towards the end of the run (or even later

), trying to brighten and colour up that a little oldfashioned Ikora look, and adapting it to 1950s fashion.
Michael