These 4 small oiling squirt cans are completely made of metal and from around 1940. These measure ca. 5-7 cm or 2-3 inches in diameter. They are non signed but all a little different. The 2 standing ones are so called thumb oiler, where the 2 flat one are pocket oilers. They are all complete and all I can see is some signs of use as small dents in 2 of the sprouts.
These small oil cans are in good vintage condition but not tested for daily use, so sold as a collectable or display item. These were used for a wide variety of smaller mechanical machines. Back then machines did not only require often regular maintenance but had to be oiled “on the fly” when they were running dry. These were used on motor cycles, bikes, typewriters, sewing machines, kitchen appliances and so on. Do read a little more about these interesting items in the blog post: great collection: miniature oil cans.
Check out the video about oil can restoration: https://www.youtube.com/watch?v=vJNg53VtZVU&t=18s