Prototype Playsets
Again all from the same source, an insider at Sunbow who choses to remain anonymous, I believe these playsets were ideas for 1988.
Jem Vanity Playset (check out that outfit on Jerrica too!).  Looks like a make-up table, note the "director's" chair, which probably was a connection to Jem's new role as an actress.
Video Camera Playset: Like the Star-Stage before it, has the dual identity of being a child-sized plaything with a doll backdrop inside. 
Scooter: Looks like instruments would attach to the sides.  Maxie, perhaps not coincidentally, got her own scooter too.