In their day they were a very thin,super flexible ,extremely close shaving blade,I loved them.You never know if the edge is too oxidized to use,until you try a shave with one.If it tugs and pulls,then keep them as a piece of history,but you will know within 4 strokes of the razor...good luck !
I tried one from 1942 and found it decent. They are a tad pulling on ATG, but they gave me a DFS. They are nothing like stainless blades that's for sure.