Sorry for not replying earlier, Michael!
Ikoraīs not easy to find here either. Itīs so well known you hardly get the chance
to find it for a low price; the prices arenīt as high as they used to be some years
ago, though.
Iīve nevertheless bought 3 or 4 within the last weeks. One in a shop (for a tenner),
one misidentified from an auction house and a lot of two from another auction house.
Iīm still a bit undecided about one of the latter as it is quite unusual and I -alas- still
havenīt found the right book in my cardboxes...
Iīve decided only to keep the unusual one apart from my uranium ones, but Iīd agree
they are quite stunning pieces especially when you look at those with scarcer colour
schemes.
Concerning your lamps...
You shouldnīt worry too much about the remaining 10 or 15%. The variety is immense
and as long as thereīs no more convincing theory - Occamīs razor...