Anyone ever seen one of these? (jackknife)

[rpmerrill]

Here is a "jackknife" that my Dad always kept in the same box with his Luger and holster and P38 from WWII. (I'll be posting many photos and questions about the Luger shortly.)

The knife blade is about 4.5 inches long and the unfolded knife is about 10 inches. It looks handmade/home made but there is an interesting mark on the blade. (Crummy steel.. no edge to it.)

Just because it was kept with the guns I thought it might be interesting to someone in this group.