While on the net today I found a grrreeat site for old sirens and lights and found just about every light on the Ecto 1... Here are some pics of the lights etc....

Federal WG 12-volt siren:

www.sirenman.com/complete/s44.jpg

Federal Model 19 "Propello Ray":

www.sirenman.com/complete/b51.jpg

And for the decklights the manufacturer wasn't known but:

www.sirenman.com/complete/b58.jpg

Ok now you can buy the siren from the guy but the others aren't usually sold... It's a private site so I'm sure if you need any of them you can contact the guy and he'll keep an eye out for you...... Obviously the main site is: www.sirenman.com. Oh and rest assured, I did alot of research and these are definately the parts used in the movie, so if you are a perfectionist like me and are building an Ecto 1 there you go....