I recently purchased this little cutie on eBay. It's a Structo Artcraft 240/4 (4-harness). It's 15 inches long x 10-1/2 inches wide x 13 high and has a maximum weaving width of 8". The loom came with a 15-dent reed. If the reed is slayed two threads per dent (for a sett of 30 ends per inch) the loom could accommodate 240 warp ends.
The Structo Artcraft loom was originally produced by the Structo Manufacturing Company of Freeport, Illinos. The company was started in 1908 and was the producer of metal toys. In 1921 they began producing toy weaving looms. Later, the toy looms were discontinued and actual standard weaving looms were made. The looms were manufactured until 1972 when the loom business was sold to the Dick Blick Company who continued manufacturing the looms until 1981 when they decided to take them out of production. Dick Blick still holds the manufacturing rights to the loom.
The Structo Artcraft looms were sold through retail outlets as well as mail order. They manufactured both pressed steel and wooden looms. In 1930 Mary Meigs Atwater wrote "Manual of Instructions for the Structo Artcraft Looms: Nos. 240, 420, 600". Atwater sold the loom through her Shuttle-Craft Guild mail order business.
The looms were popular workshop looms and for weaving samplers. For more information visit this website or join the Yahoo group all_things_structo.