3A is a Kodak term for 122 film cameras, so unless there is something mislabeled or a part that was moved from one camera to another, I think that you have a 122 camera. I would open the back and do a rough measurement of the film gate, if it is a little over 5 X 3, it is almost certainly 122 film. For 120 it would be more like a little over 2 X 3, a really big difference. For 116 film, I would be about 2 1/2 by 4 1/4. Since the width of the 116 is fairly close to that of 120, folks have been able to modify the camera to use with 120. I can imagine doing the same with a 122 camera, but the job would be a lot more involved.
Also, I would inspect the back and inside for embossing or labels, usually there was something from Kodak to indicate the film used. Often this labeling survives. I have a box brownie of some sort sitting right here and it has "Use Film No. 116" embossed in the leatherette on the back. My Kodak folding Boy Scout camera has a label on the inside.