So this is what I have.
so these tapes seem to be rare in members collections. I like to display mine as a makers match to a box and when no demo available i use branded blank cassettes Aiwa metal for aiwa/Pioneer blank for disco robo.
I also have a Panasonic digital headphones demo tape with my collection of vintage headphones and two sharp boxed demo blanks.
Something else I noticed is that all Sanyo demos are a play head down style vs all the others as a head up style, time to check those Sanyo mechs for orientation.