yup - more often than not the only thing that gets real specific to a machine (other than short/slant shank) is the feed dog cover plate. Though if your feed dogs drop, you don't really need the cover plate as long as there is nothing the upper guide plate is going to get hung up on.
Now you've got me looking for a Magic Key buttonholer for my White. It is the same design as the Singer - I believe Greist made them all.