Mickey2

I like the moss green and gold of the Viking machine. The japanese clone has the added feed dog knob, but it looks more turquoise than green? The Viking is one of the first machines to be given a color other than black. I have seen a shiny version of the model 12, as well as the non-shiny you have (both green). If I remember correctly, it's not nearly as crinkly as some. This is a model introduced in the early 1930s.

I think the Japanese international delux is at least a decade later than your Husqvarna. These were made from the 50s and well into the 60, pretty much identical except for color and minor alterations to the exterior. At some point Husqvarna added a numbered dial for the top tension mechanism, but I'm not sure when. By the time the Japanese had ventured into all kinds of colors and slight changes to the exterior, the production of Husqvarna 12 had ended. The Japanese straight stitch clones were made well into the 60s.

On the Husqvarna machine is the bobbin case, the occilating hook and race are derived from singers model 15. As far as I know, all other parts are different. On some of the early Japanese clones each and every part is equivalent of a singer part number. The alterations came gradually, and in the beginning not much at all. The Husqvarna 12 had a very different point of origin, not Swedish culture as much as European sewing machine culture. It started way before WWII. I think German brands had models with similar hook and race to class 15 before 1900. Eventually they turn to various rotating hook and race developments. By the 50s most makers aimed their efforts at swing needle zigzag machines. Bernina introduced their first free arm zigzagger in 1945 and every body had to keep up.