Pre 1958 because of the name, probably pre 1920 because it is a saunders type. Nye patented several sliding type cutters after that era.
(But then again, see 1916 patent 1177721 ....)
Still not certain tho, there is a lot of confustion about the saunders type, there were patent lawsuits etc etc...
(At least some of the soil cutters say Pat Pend )