Lot of Durham Duplex Razors (4)

Vintage Durham Duplex razors- all in excellent condition. Four (4) boxes of unused blades. One of the boxes has been opened but the blades look as if they have not been touched. The other boxes still have the seal on the inner wrapping. I am not sure of the exact age of the brush. I would guess the 50s or 60s. The thin plastic on the brush's box is torn but the brush is unused. This is a collection I inherited so I am not personally familiar with the use of these types of razors. They all seem to be in pristine condition with no rust.