Your reply is somewhat complicated, and I'm not sure I always follow your point--so I have not answered prematurely.

My first reply would be this: can you think of any other instance in which a "sample card" has been made with the intent of providing beads to be copied? As far as I know, sample cards solely served to provide bead sellers with examples of beads they could purchase for resale. In point of fact, sample cards now provide a bead historian with a look at past productions of the company involved, and demonstrates what beads were made at the same time(s), (though the intent was not originally to provide historical information).

That the beads may be "too coarse for the European market," is a judgement. Perhaps the card was not made for the European market (!), but was made for export purposes, such as MANY cards were made. Perhaps the seller took a chance that some audience would be intrigued by "primitive foreign beads" in any of several markets—including in Europe. (It might be that the attempt flopped, because—as you say—the beads might have been too coarse to inspire much interest. But still, the attempt may have been made to market these beads.) Let's remember, for instance, that Picasso made "primitive" African art an international celebrity in the early 20th C., and instigated many people to become interested in it and to collect it.

These are my thoughts at the moment.

Be well. Jamey