This one in particular is at least a 1989 model due to the chrome on the c-pillar. It was added in 1989 for the police/taxi/fleet LTD Crown Vics. The LX models had them through the 1988-1991 run (not sure about the 1979-1987 LX models). The changes I am making are strictly for the fleet-type models.
I've learned not to trust the brochures as I've noticed that Ford (and I'm sure other companies) recycle photos from one year to the other. Take this 1990 Ford LTD CV Police Brochure. The model in the picture is clearly older due to the lack of c-pillar trim and the older hubcaps. If you look up more recent Crown Victoria police brochures, you'll find the same recycling of images. Brochures are good for technical information, but not always necessarily for picture references.
The 1989 and 1990 brochures you linked to recycled the images Ford used for the 1988 brochure. I've seen it done many times over the years. If there are no major exterior changes, the car companies don't always bother to do another shoot for the actual model year car. If you notice, the 1990 brochure clearly shows an LTD with 1988-1989 hubcaps.
It's specifically a 1988 model due to the hubcaps and lack of chrome trim along the bottom of the c-pillar. It has the clear bottom turn signal lenses of a 1991 model.
This is specifically a 1989 due to the older-style dash and the chrome trim along the bottom of the c-pillar. As was said before, it has 1990-1991 hubcaps.