Basically, you folks have pretty much covered the ground with regard to this topic.
Very little is known.
Based only on the slimmest of inferential evidence I do not buy the Spanish market theory, simply because I have also heard stories of these pens having been sold out at discount prices in the company store sometime in the '90s.
My assumption is that the company made some unknown number, they failed to sell and they won't do it again.
But, again, I am working from a purely inferential basis.
For the record, Jürgen Dittmer, the Pelikan archivist, supports the Spanish theory, in person and in the book.
But I just don't buy it and I can't even say why, except that it does not seem logical. If the pens were sold successfully in Spain, and if they now are cult objects, then the company would make more. On the other hand if they took a bath on them (as they have with other tortoise models) then they would not.
No mention --at least, I cannot see it-- to Spanish vendors or the like.
There's very little specific information available about where in the Spanish market the pen was made for, who sold by, etc. As I suggested, you might well try sending a message to Rick Propas, who is one of the more knowledgeable people with respect to Pelikans.