Heater Hose Sheathing Question

A question for 1987 GLHS owners (but 86 owners can feel free to chime in as well): Do your heater hoses have a plastic sheathing around them? Mine has covering that looks like this http://www.ebay.com/itm/100-Ft-5-8-I...UAAOSw-itXwHwN
I would like to determine if it is factory, or added later by a previous owner.

Thank you,

It's original. After 30 + years, it's usually gone.

Thank you. I'm not surprised it's usually gone, mine is getting to be in pretty rough shape.