This is the siren that I got from Skokie, IL.
It had the dual tone chopper in it (which is in my detroit one for now).
and it does have the taller box and wire cutouts on the rain cap for the rotator. But the rotator box didn't have a ID tag. only the compressor did.
It has the Federal Enterprise logo on it.
It was mounted on a tall standpipe with guy wires and was on a bus building.
So my guess is that it may have started out as a 1003, but later on was converted to a 1000T. But the weird part about inside the the rotator box, is there is no evidence that it ever had the extra contact "wheel" on the chopper tube or the interior platform. So it's a mystery.