on the AP kit, of which I am quite vocal around these parts, the back is not separated at all,
the suit was created partially from an ROTJ suit to begin with, and it's ABS.
most of the TE/TE2 line comes with those back plate parts separated, so
it's really ready to go ROTJ almost out of the box.
just assemble it with the overlap method, instead of the butt joined and finishing strip.
all you would have to do to make it ROTJ, thinner webbing belt,
put the AB buttons on upside down, add the proper car door edge trim-
if you let AP know that you're making an ROTJ he can sell you the door edge trim as well!
AP's holster is not correct, as he sews the bottom shut. and you'd need longer straps for the holster
for the ROTJ style.
the blaster and handplates, and one of joe's ROTJ helmets, and your fan film would be well on it's way to
accuracy.