It really depends on what you want the curtains for. If you want to keep out UV, and prying eyes, but mostly want them open for the light, then washable and easy to open is important. If your only concern is prying eyes, and you're not worried about stuff fading below, then you can make posterboard fill ins for the clear part of the port, and pop them in, just by cutting it to a pressure fit. If you want light in and no prying eyes, I've seen an arrangement where a creamy plastic that let light through but you couldn't see through it, slid on a top and bottom rail to cover the port.
The rail or track above your port is not one I am familiar with. I was thinking I'd remove it and install some time of raise & lowerable shades. However if it is a standard Hunter
thing, maybe they could clue you in as to what's missing and where to obtain what you need.
Good luck with it.