I haven’t had time to research what car brand and model this is for, but it is a similar design to the Mercedes Pontons and 300 series. Although the chrome arms are a little different you can use this as a base to make the shape more rectangular like the Mercedes.

Look at the last two photos and you will see that from the mounting on the side of the headrest the chrome arms bow outwardly and then back to go straight into the female. The space between the female receptors would then have to be about 19 inches.

The leather is in excellent supple condition with just the one spot that can easily be dyed. That is not a hole, just the color worn down to the original hide.
The chrome is in beautiful condition with no pitting.
The foam cushioning is great.