Yes Nigel, that is the same descripton in my catalogue, only in German (23 mm lang, Wioletblau etc). I`m pretty sure mine is not a valuable Libau stamp (at least for the simple fact I am not used to have valuable items in my collection

, and here I strictly mean CV). But if not`s a telegraph stamp, there`s only one thing I could think of (tertium non datur?!)- it`s fake. Another problem is I can`t remember from where I got this one

.