Founded in the 1950s, Tokyo, Japan.
An American toy importer, similar to Cragstan, which specialized in importing Japanese mechanical and battery operated toys.
Rosko appears to have been most active from the late 1950s through the late 1960s after which they disappeared from view. They are best known for their logo type "Rosko Tested Toys".
What's it worth? Take a look at this Rosko price guide: sold listings for a value indication.