Help ID oiler M1 Carbine / 1903 Krag ?

[mwrookie]

They look like after market M1 carbine oilers. Some early M1 carbine oilers were marked on the bottom to different makers. Later carbine oilers were marked IS all in a circle. BK, SN with a number. There is an SW on the cap that has been up for debate. And a Poly Brothers.

Thanks Jim, Great info and pictures!