Miniature Vintage Bosch Spark Plugs

We have found in a dark corner of one of our warehouses a small quantity of brand new miniature Bosch Spark Plugs of a very early design. Probably for a model engine these would appear to be from the 1st WW period or perhaps a little after. They are 12mm and constructed in exactly the same way as a full size Bosch aviation plug of that period. They come complete with ignition lead clip and their original box (most have been opened unfortunately).