Here are some pics of my LOTR with some add-on figures which are all from the original Play Along toys. For some reason I did not get the camera to focus well but the general layout can be seen. The only thing I changed from the original figures is that Sauron is at the Barad-Dur tower where he belongs, and the Uruk holding the head was inserted on the right pop bumper instead of next to the tower. Gimli is added on the pop bumper behind the Gimli Hole. Boromir is on the left Pop. Legolas is on a custom made plastic I made attached to a screw on the path of the dead. Arwen is also on a custom made plastic.
On the sword, I have the Witch King and his Nazgul buddy reaching toward the general direction of Frodo. All of these mods have been done without damaging any plastics so they are reversible, except the pop bumper figures. I bought spare pop bumper caps to have in case I want to remove the figures which are attached through the caps with screws.