Vintage Watercolor Tube cheapest Aluminum Box and Pallet

Vintage aluminum travel art box with built in pallet and 16 tubes of watercolor. The art box is marked Artra-Artra. I can not find anything about this company. There was another company back in the 1920's who made boxes like this one. So I can not date the box, the paints are mainly from the 1970's. All paints are Windsor-Newton. The paints have been used to some degree. They are all usable, I threw away the dried up ones. The travel box shows wear, She must of liked mixing the paint cheapest in the upper left, the plastic is worn thru to the metal. Dried paint, scratches to the outside and a ding or two. This one has thumb holds on the back side.The box closes and locks. Measures 9 ¼ inches long and 4 ½ inches wide.