Seems like those old Japanese machines came with disk/cams or had a cam stack. Some had plastic cam stacks and some had metal cam stacks. They are fun to play with once they are set free of gummed up oil. The Tri-Flo works wonders on that. When it is gummed up every moving part on the machine is suspect. I think the ones with cams are just a bit easier to set free - they are simpler. I had a MW machine sort of like that one with the stitch selector on the top. I'm thinking it was a lot like Bernina in that area. I don't know if it was a knock off or made by the same company for MW or what. I do know I liked the machine and probably sold it too cheap - I hope the kid that bought it was very happy with it - it was made by Happy I think.