Interesting 'spoons !
It must be quite difficult to spot the clear layer ?......
You have prompted me to examine mine and from the base rim it also appears to be 3 layers !
(http://glassgallery.yobunny.org.uk/albums/userpics/10006/1903%20007-2.jpg)
3 layer would indicate better quality, ditto eveness of color which does seem to be a Scandi trait but that's all I can say.
Don't discount the Italians too quickly - there are all grades of quality from Italy.
I would dearly love to pin down where my 3 KG (without fittings) monster cam from. I fell so much in love with it that I actually went to Holland to pick it up !! (OK along with some other stuff ....aaaaah those were the days .....)
Is yours heavy too ?
Does the bulb go in from the bottom or the top on yours ?