As far as I can tell this style of small parts box, with a picture bordered by grey strips with stars, was only available in 1920 and is a sort of hybrid of the earlier large boxes that only had printing on them and the fairly recently introduced smaller boxes with the picture of the boy with his crane. Despite the short-lived nature of the boxes they appeared in Meccano brochures right up until 1925 as the blocks from the 1920 brochure continued to be used until the "New Meccano" came out in 1926. The 1920 No.6 had four of these boxes as there were still 465 nuts and bolts in the outfit that took up three of the boxes. By 1922 the nuts and bolts went down to 300 and one of the boxes was dropped.