This is an old set from the very beginning of LEGO, when the construction toy was called "AUTOMATIC BINDING BRICKS". The name "LEGO" does not appear on the box or bricks and in a booklet that may, or may not, be part of the set only the name of a Swedish plastics factory is mentioned. We know this is a very early set because of the colours and the plastic used.

The plastic used in the first batches was in all probability a thermoset catalin (phenol formaldehyde or urea formaldehyde) as used in England at the time and results in an extremely shiny product. In this case the bricks show a somewhat milky overall aspect and a degree of transparency against a soft bulb light that does not occur on later products, which are less transparent or even opaque. The figure at left compares a "normal" brick as used in the early 1950s (single slot at far left) with a yellow catalin brick from this box (on the right side).

The box illustrated is complete and original in its complement except for a few missing 2X2 bricks (2 green, 2 white and one yellow) which have been replaced by very different issues so as to be easily identifiable. The constructional booklet is missing one page but its belonging to the box is not assured. The two images come from another set of the same approximate date and were intended as decorative fillings for frames that were suggested as a constructional application.

The complement of the box was sixty 2X4 bricks and sixty 2X2 bricks. For each of the five brick colours (milky white, dark green, milky yellow, dark red, and medium blue) reproduced above:

-Ten 2X4 bricks (Six with two slots and four with one slot);

-Twelve 2X2 bricks (Six with two slots and six with one slot)

There were also: four doors (in this set two green, one red and one white), six 8-pane windows (two of each colour); six 6-pane windows; and six 4-pane windows.

The bricks were laid in a checkered pattern, as seen in a contemporary picture.

This sort of box, without a reference to "LEGO", was sold as late as 1951 and it is (still) a mistery why LEGO, so eager to mark its products from an earlier date, sold the Automatic Binding Bricks sets without a mention to its brand and, even, under different brands. This was certainly done in Sweden but I'm not a 100% sure that boxes sold in Denmark were also devoid of the brand name.

At the time this box was sold (circa 1951) a 10X20 baseplate was already offered as a part that could be purchased separately, as shown in the booklet, but was not included in the box.

It is likely that in 1952 or 1953 the bricks had already lost some of their early colour variability and that the rarity of some of the colours in this box derives from the short time span of their use at a time of low production.