This is true, take for instance, camillus makes remington's knives. They did in the 1930's (if I remember correctly, or it may be in the early 40's). They also do now.
Camillus has made knives for others, schrade use to. Schrade made some of the buck stockmans, camillus also made some. Queen has made them for others. Boker makes henckels whittlers now and the list goes on and on, etc. etc. etc. Many have done contract work for each other, its been that way for over a 100+ years.
Just like the old primbles, made by different companies. Now the rights to it are owned by bluegrass cutlery.