These are some I've collected over the years.The Gerber and the SOG were gifts from my son.I have several older ones in my tool boxes in the shop and will have to dig them out to see what they are.
Combination tools were made by several knife companies but never seemed to be too popular as most of the remaining ones are usually found in near unused condition.
The first one is a Case XX Knifax with wood scales. They were also made with genuine stag and bone.Like all combination tools they are strictly light duty items.
The next one is made by Colonial Knife Co.These were available as either a single piece or combined in a common sheath with a small fixed blade and sometimes a scout/utility folder.
Third is one made by Keenwell Mfg Co which was a forerunner of KA-BAR knives.When I bought this one the sheath was in terrible shape and resisted all attempts at repair. Miraculously I found one(along with an extra ax blade)on e-Bay! KA_BAR also made a knife/ax combination tool.
Last one is a Western.The two knives did not come with it but have the same handles. I am thinking of having a sheath made to house all three.