I bet if you went to a door/window seller (not big box, if possible) you might find what you are looking for. I have a door from the 90's that has removable inserts and it has a similar type system, although the cam is shaped a little different.
As a last resort, you could probably make one out of sheet material that is the same thickness as the original.
Whether you think you can, or you think you can't, you are right. - - - Henry Ford