Thanks for the suggestions greaterexp & KenmoreGal2.
ISMACS is rather dismissive of the post WWII Japanese imports, from what I've seen on the site. I belong to several similar Yahoo groups - I'll have to take a closer look.
The model 158.750 might just be acquired for display if the colors are bright. I can't really tell the shade of pale blue and whether the yellow is meant to be yellow or just discolored. I'll grab pictures if nothing else when I see it tomorrow.