When talking about traditional knifes, I am thinking about both folders and fixed blades, examples would be the Scandinavian Pukko style knifes, the french Laguiole folders or maybe the US Bowie knife.
So let´s see how this goes and let me start with a traditional Austrian knife, the European country I live in:
It is the "Taschenfeitel" ("Tasche" meaning pocket, "Feitel" slang for knife, see attached pics below). A very simple design, just a round wooden handle, no liners, no locking mechanism, no real pivot (blade just pinned in), blade shape featuring a big "hump", a lot like the one the Spyderhole is placed in (no hole of course in the Taschenfeitel, just a nailnick). Normally just about Delica size
When I was a boy in the late seventies and early eighties, almost every boy in the more rural area I was born and raised kept such a knife in his pocket - you really HAD to have one, they came in various colors (I´d always choose a blue one...

When you look at the attached pics below: It DOES remind a little of the Delica, doesn´t it? Even in the color-choices...

Now the historic, very interesting part:
This type of knife was produced in Austria in the current shape since the SIXTEENTH Century (starting at around 1550) , and they used a type of steel ("Scharschachstahl") that was normally reserved only for weapon manufacturing.
So in some way it is an ancient predecessor of the Delica...

I´d encourage you to post YOUR traditional knifes and Spydercos lookalikes here!