During a Google image search, I happened to come across
this interesting photo. I'm not sure of the context, but it would appear to be an advertisement from an old magazine or catalog. The three kits in front are the "Mega Up" kits you might be familiar with. That line of kits only featured the main trio. However, this photo shows the 4 rescue members along with them, and upon close examination they do
not appear to be the models that we're familiar with from the other line of KNT kits (the Edo-Mae Sets). It would appear that the Mega Up line was intended to have more kits at some point. Another old Bandai flyer that was up for auction some time ago featured a Karamaru kit that was never released, so it would seem that quite a bit of KNT merchandise was planned but eventually cancelled.