I believe this first knife (item 6889) in this 1924 Henderson catalog to be the knife , making it's appearance years before being shown in the Schrade catalog E 1936 supplement.You will notice the thickness of the pruner is like the one I posted.The later Schrade pruning blade on farmers jacks were like the upcoming GEC #38,a little slimmer and seemingly more elegant,staying a little more covered in her nest.
Page from 1924 Peter Henderson catalog(item 6889). Mine like this is one of my favorites,I like it a lot,,and it also has some personal history to me.
Here's the different pruning blade shape in this 1939 Henderson catalog ( knife is item k-7).


