Here are a few folding scissor tools of mine. These are actually "newer" ones, dating from the 1930's - 1950's. They have a coil spring located between the scissor jaws. There are even older models that use the backspring of the handle instead of a coil spring.
The handles fold up in a butterfly style, much like many modern multitools. The knife and file blades are outside-opening.
I've found them in two sizes. By far the majority are like the one shown below and measure about 2-1/4 inches (57mm) when closed.
A small catch on the end unlocks the handles, then it just opens up like so:
The one above is marked BONSA, which was a cutlery firm in Germany. It has scales made from a hard, polished, fiber material. The one below is marked PATENT and has a clover leaf logo. It has scales made from striped plastic.
This larger one measures 3-1/4 inches (83mm) when closed. I've only ever seen two of them. Scales are red plastic, liners and pins are brass. It too is marked PATENT and has the clover leaf logo.
The only relevant U.S. patent I've found dates from 1907. It was filed by Friedrich Klever of Solingen Germany, which not coincidentally was the center of the German knife-making industry. *Note that this very patent was the one Tim Leatherman made reference to when filing for his original 1983 patent.*