If you are looking for usability the Japanese Swinger clones are a great buy and hard to beat because they are generally all metal. Post war, Swinger gave Japan their old blue prints to help reconstruction and the Japanese took that and ran with it. Japan was not big on branding in the 50's so it's next to impossible to figure out who made what and they'd stamp a lot of different labels on machines. Because of the lack of branding they are not collectable at all today. This makes them dirt cheap tanks if you want to actually use it :)

Mine is also a ZigZag model to compete with Swinger but unlike swinger's more elegant design my Japanese machine moves all of the internals back and forth instead of just the needle LOL.