While looking for details of the WM-FX999 I came across this site which has lots of interesting pictures http://sakamatra.blogspot.com/#!/
Lot's of photos on that site, too bad there's not better descriptions but there is some unique electronics.
and another, found while reading the comments in CassetteComebacks metal tape Youtube review http://vintagecassetterecorder.com/
That's an interesting site, it looks like a well done ebay redirection site. I don't have a problem with it, I like seeing the historical listings as well as the newer one.