Thanks for all the responses! I am quite sure the 1973 date is accurate because the factory tags with the information in both Chinese and English were still attached to the handle of the carrying case. Here's a picture of the case, which is wood covered in the suitcase like material you see. I'm not sure what that is, but it's in great shape except for some rubbery piping that came loose at one edge. It's very strong and latches onto the bottom wood box very securely, for which I'm thankful because I wouldn't want that to fall on any toes.
The case had an airline tag on it indicating that it was in Okinawa at some point, but I think that is evidence that the husband of the Taiwanese woman who owned it was probably US Army. I don't think this machine would be rare near where it was made, but most people would opt to buy a new machine rather than pay to ship one this heavy. If the army takes care of the shipping, it's another matter. They must be rare in the US because I'm not having any luck finding information, but perhaps if I knew what they called it, I'd do better. The name is in Chinese characters on the front.
I looked up what kind of current and plugs they use in Taiwan and learned that it's the same as ours in the US, so that's why the foot pedal and wires look to be original, and another reason it was worth the long move. I think the woman whose machine this was probably would have been a little girl in 1973, judging by the age of her son who sold it to me. Most likely she got it from her mother.
I will take a picture of the cams compartment on the front of the machine and show you that, too. BRB.