No NO Glen this confusion is my fault.
My american friend ( a glass collector and dealer of 10+years) initially told me that it could not be American Carnival because of the rim.
I omitted to mention this in my initial post.
Adam, when you drew attention to the rim and said it was fire polished I thought thats all there was to it.
However, having questionned Terry in Iowa again about it, apparently its not the fact that it's fire polished but that its irregular/ knobbly / not smooth. This style of rim is not seen in American Carnival he tells me.
My apologies for leaping to conclusions !
(PS I still think its Bohemian - Depression Era ? probably - Carnival ? still open)( Glen surely there were other Bohemian makers of Carnival apart from Inwald ?)