It's been a while since this discussion, and I've been baffled by these sculptures ever since. However I just came across [
this] old post on Collectors Weekly, where a Spanish company called
Viartec THF is mentioned. After some googling, I found a few examples, with labels that read
"Viartec Hand Made in Spain":
[
Example 1]
[
Example 2]
[
Example 3]
[
Example 4]
The label can be seen best in the last one. I also found [
this] listing, no ID or label, but the seller claims to have brought it back from Spain in the 1970's. If these were sold in Spanish tourist shops in the 70s, it would explain why there are so many of them here in the UK!
This doesn't explain the Davidson label or the Icet label of course, so there is still a bit of a mystery!