The first Minox negative wallet appeared in 1938, along with Riga Minox. The VEF Minox Riga wallet had 5 sleeves holding 10 negatives each, for a total of 50 negatives.
Once a common accessory sold by Minox company, it slowly became a collector item, because no large quantities can be found on sale. The avid Minox negative gatherer is going to have a hard time finding enough numbers of this precious item.
Having said that, let it be known that Jimmy Li has revived the production of this neat and helpful piece of Minox accessory, as seen here:
If you wish to purchase, email him here (firstname.lastname@example.org).