I've love toppers and made a few custom toppers for my games and even hooked them up to interact with the games by piggy backing off flashers or the GI.
Roadshow, I found a Bob the builder dozer at a second hand shop for less than $5 bucks and mounted two white LEDs on top of it with red bulb condoms. Painted a scrap piece of wood black, bought a reflector from Princess Auto and put a flasher inside it.
Judge Dredd, mine didn't come with an eagle topper nor would it clear my low ceiling anyways. So I had a friend re-draw one for me to fit and I broke the image down into 3 layers so the claws can fill in the gaps on the head and also give the illusion of depth. I printed it out and mounted on foam board and used some "L" brackets to make it stand up. I also wired up two flashers behind the tip of each wing and depending which pursuit ramp is flashing it will go off with it.